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$30/hr
100%
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$100K+ earned
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⭐⭐⭐⭐⭐ "𝘞𝘦 𝘸𝘦𝘳𝘦 𝘷𝘦𝘳𝘺 𝘩𝘢𝘱𝘱𝘺 𝘸𝘪𝘵𝘩 𝘵𝘩𝘦 𝘨𝘳𝘦𝘢𝘵 𝘸𝘰𝘳𝘬 𝘲𝘶𝘢𝘭𝘪𝘵𝘺 𝘈𝘯𝘯 𝘱𝘳𝘰𝘷𝘪𝘥𝘦𝘥 𝘢𝘯𝘥 𝘵𝘩𝘦 𝘕𝘢𝘵𝘪𝘧𝘦 𝘔𝘰𝘣𝘪𝘭𝘦 𝘵𝘦𝘢𝘮. 𝘐𝘧 𝘸𝘦 𝘳𝘦𝘲𝘶𝘪𝘳𝘦 𝘢𝘯𝘺 𝘸𝘰𝘳𝘬 𝘢𝘨𝘢𝘪𝘯, 𝘸𝘦 𝘸𝘪𝘭𝘭 𝘥𝘦𝘧𝘪𝘯𝘪𝘵𝘦𝘭𝘺 𝘶𝘴𝘦 𝘵𝘩𝘦𝘮."
🤝 𝐈 𝐜𝐨𝐝𝐞, 𝐚𝐝𝐯𝐢𝐬𝐞, 𝐚𝐧𝐝 𝐜𝐚𝐫𝐞 𝐟𝐨𝐫 𝐲𝐨𝐮𝐫 𝐩𝐫𝐨𝐝𝐮𝐜𝐭 𝐥𝐢𝐤𝐞 𝐢𝐭’𝐬 𝐦𝐢𝐧𝐞 𝐟𝐫𝐨𝐦 𝐭𝐡𝐞 𝐬𝐭𝐚𝐫𝐭. 👋 Hi! I’m Ann an Android & iOS mobile app developer Swift Kotlin mobile app development expert with 8+ years of experience building high-performance iOS apps, Android apps, and scalable cross-platform solutions with React Native.
🚀 Android & iOS Mobile App Developer | Swift • Kotlin • React Native | Mobile App Development
As a Top Rated Plus Android & iOS mobile app developer Swift Kotlin mobile app development specialist on Upwork with 30+ five-star reviews and a 100% Job Success Score, I’ve helped 60+ companies and startups transform ideas into scalable, future-proof mobile products.
Whether you need a native iOS app with Swift, a native Android app with Kotlin, or a cross-platform solution, I deliver Android & iOS mobile app development using Swift and Kotlin with precision, creativity, and enterprise-grade quality.
From e-commerce, fitness, and healthcare to fintech, streaming, logistics, and wearable apps, my experience as an Android & iOS mobile app developer Swift Kotlin mobile app development professional spans 15+ industries and 50+ published apps.
✅ Why Partner with Me as Your Android & iOS Mobile App Developer:
8+ years of hands-on Android & iOS mobile app development using Swift, Kotlin, React Native
50+ successful iOS and Android apps delivered in Fitness Mobile App (Coaches, Gyms & AI Meal Plans)
10+ successful iOS and Android apps delivered in Fintech industry
A strong mobile app development team of 50+ experts
100% Job Success Score and consistent 5-star reviews on Upwork
Streaming, TV apps
GPS and Map-based apps ( GPS trackers, MapBox, Google Maps integration)
AI Mobile App Development
MVP App Development for Wellness and Hospitality Platform
Dating Mobile App
Social Media App Development
Mental Health Social Platform
Enhance an Android, IOS mobile apps
Figma designer. UX/UI designer
Real Estate mobile apps
Full-cycle Android & iOS mobile app development — from idea to App Store & Google Play launch
AI App Expert specializing in Swift Kotlin mobile app development, on-device ML, real-time image & text processing, and LLM API integrations
🔧 Services I Provide as an Android & iOS Mobile App Developer (Swift & Kotlin):
Native iOS app development with Swift & SwiftUI
Native Android app development with Kotlin & Jetpack Compose
Android & iOS mobile app development using Swift Kotlin architecture
React Native app development for cross-platform solutions
UI/UX design for iOS and Android apps (Figma, Sketch, Adobe XD)
Secure API integrations & cloud services (AWS, Google Cloud)
Scalable backend connections & microservices
Wearable app development (Apple Watch, Wear OS, Bluetooth)
Performance optimization & offline-first mobile app development
🎯 Industries I Specialize In as an Android & iOS Mobile App Developer (Swift Kotlin):
📦 E-Commerce | 🍔 Food & Drink | 📚 Education
💪 Health & Fitness | 💘 Dating | 🎬 Entertainment & Streaming
💼 Finance & Banking | 🌍 Travel | 📱 SaaS Platforms
⌚ Wearables & IoT | 🚚 Logistics & Booking Apps
All powered by Android & iOS mobile app development with Swift and Kotlin.
🚀 Advanced Features I Build with Swift & Kotlin Mobile App Development:
✔️ Social login (Google, Apple, LinkedIn)
✔️ Real-time chat, WebRTC video calls & push notifications
✔️ Offline mode & smart data synchronization
✔️ GPS, geolocation, Bluetooth & geofencing
✔️ ARKit & advanced AR features
✔️ Firebase & cloud integrations
✔️ Monetization (AdMob, Meta Ads)
✔️ Voice assistants (Siri, Google Assistant, Alexa)
✔️ TV apps (tvOS, Android TV) & wearable tech (Garmin, Monkey-C)
💬 Why Choose Me as Your Android & iOS Mobile App Developer (Swift Kotlin):
I bring deep expertise in Android & iOS mobile app development using Swift and Kotlin, focusing on clean architecture, scalability, performance, and business impact.
Whether you’re a startup building an MVP or an enterprise scaling globally, I’m the Android & iOS mobile app developer Swift Kotlin mobile app development expert who can turn your vision into a successful product.
📱 Let’s connect and build a powerful Android & iOS mobile app with Swift and Kotlin.
🚀 Your trusted Android & iOS mobile app developer Swift Kotlin mobile app development partner is just one click away.
UPD: 05.06.2026
Ann N.
has worked
.
Associated with
Natife Mobile
$700K+
earned
$40/hr
100%
Job Success
$2M+ earned
Available now
Offers consultations
Start of list.
End of list.
About Me
I have 10+ years of experience in Project Management of Mobile App Development, specializing in Android, iOS, & Cross-Platform App Development using Java, Kotlin, Swift, Objective C, React Native Mobile, Redux Flutter, Firebase, Mongo Db, User Authentication, EHR, FHIR, HL7, HIPAA compliance, Typescripts, and AI-driven applications.
My expertise spans iOS & Android development, AI-powered solutions, seamless authentication systems, and full-stack capabilities, ensuring modern, high-performance apps for businesses of all sizes.
Our Agency
Since July 2017, my husband, our talented 55+ team members, and I have been delivering world-class digital solutions.
- 150+ apps successfully delivered across multiple platforms in the last year
- $4M+ turnover on Upwork
- 500+ successful projects, 15,000+ hours worked
- Close to a 100% success rate
- Worked with 7, 8, and 9-figure businesses
Our Expertise
Mobile App Development
• Android, iOS, & Cross-Platform Apps (Java, Kotlin, Swift, Objective C, React Native Mobile, Flutter)
Web & Full Stack Development
• Front-End: React.js, Angular.js, Next.js, WebRTC
• Back-End: Node.js, Firebase, MongoDB, PostgreSQL
• Cloud Deployment & API Integrations
E-commerce & CMS Development
• Shopify Developer & Customization
• WordPress Developer & WooCommerce Solutions
UI/UX Design & Branding
• Adobe XD, Figma, Photoshop, Sketch
Digital Growth & Security
• SEO & Digital Marketing Optimization
• Data Security & Intellectual Property Protection
Intellectual Property Services
• Trademark & Copyright Assistance
Why Choose SolidAppMaker?
- Tailored Approach: Every project is customized to fit your needs and budget.
- Agile Workflow: Regular updates, milestones, and transparent communication.
- High-Quality Development: Rigorous testing & performance optimization.
- Competitive Pricing: Top-tier services at fair and transparent pricing.
- Proven Track Record: Experience with MVPs, SaaS platforms, AI-driven apps, and enterprise solutions.
Why SolidAppMaker Stands Out
- 8+ years of expertise in UI/UX, mobile apps, SaaS & web development
- 510+ projects successfully completed for startups & enterprises
- 10+ awards & recognitions, featured on Upwork & top design platforms
- 20+ countries served, delivering top-tier prototyping & development solutions
Industries We Cover
Healthcare, Transport, Retail, Asset Management, Real Estate, Dating, Nature/Wildlife, Rental, Food Delivery, Fintech / Finance and Banking, Cryptocurrency, Entertainment, Hospitality, Logistics, Manufacturing, Media and Publishing, Non-Profit, Sports and Fitness, Travel and Tourism, Utilities, Wellness, Medical Dashboard, Marketplace, Advertising, Automotive, Business Innovations, Ecology, Human Resources, LegalTech, Lifestyle, Fashion, Marketing, Navigation, Education, E-learning.
Highlighted Skills
Project Planning, MVC Architecture and RESTful APIs, Front-end Technologies (React.js, HTML5, CSS3, JavaScript), Responsive and Mobile-first Design, Database Design and Implementation (MongoDB, Firebase), User Authentication, Integration of Third-party APIs, Deployment to Cloud Platforms (AWS), Test-driven Development, Agile Methodologies (Scrum, Kanban), Security Technologies, QR Code Scanner, GPS and Mapping, Blockchain and NFT, ChatGPT and Artificial Intelligence.
React Native Mobile Developer 10+ years of experience
As a Mobile App Developer and Full Stack Developer with deep expertise in SaaS Mobile App, React Native Mobile App I bring over a decade of experience in building high-performance cross-platform mobile application.
As a talented React Native Mobile Developer with good knowledge of cross-platform development, I specialize in crafting high-performance mobile apps for both iOS and Android platforms.
I made more than 400 apps using React Native Mobile.
Reactnative Mobile is my main tech stack, making top-performing apps using React Native Mobile.
IOSDeveloper AndroidDevelop
As a mobile app developer and full stack developer, I specialize in building robust cross-platform solutions using Flutter, React Native Mobile, and Expo for rapid development. My projects often leverage Firebase for secure real-time data storage and user authentication, and I have hands-on experience integrating WebRTC for live video and audio communication inside mobile apps. On the backend, I frequently use Laravel to build scalable APIs and admin panels that perfectly support mobileapp solutions. ReactNative
Next Steps – Let’s Build Something Amazing!
📅 Would you be available for a 30-60 minute free consultation?
During this meeting, we will:
- Go over your project goals, technical needs, and budget.
- Provide a project plan with a timeline and cost estimate.
- Discuss the best development approach to fit your vision.
- Send me a message, and I’ll share the Upwork scheduler link so we can set up a time that works best for you.
Looking forward to collaborating and creating something extraordinary!
Best regards,
Daisy VC
Daisy V.
has worked
.
Associated with
SolidAppMaker LLC
$1M+
earned
$30/hr
100%
Job Success
$90K+ earned
Available now
Offers consultations
Start of list.
End of list.
🏆 𝐓𝐨𝐩-𝐑𝐚𝐭𝐞𝐝 𝐏𝐥𝐮𝐬 𝐌𝐨𝐛𝐢𝐥𝐞 𝐀𝐩𝐩 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 (𝐓𝐨𝐩 𝟏𝟎%) 🏆 | 𝟏𝟎𝟎% 𝐉𝐨𝐛 𝐒𝐮𝐜𝐜𝐞𝐬𝐬 𝐒𝐜𝐨𝐫𝐞 | 𝐢𝐎𝐒 & 𝐀𝐧𝐝𝐫𝐨𝐢𝐝 𝐀𝐩𝐩 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 | 𝐒𝐰𝐢𝐟𝐭 | iOS App Developer Swift | 𝐊𝐨𝐭𝐥𝐢𝐧 | Android App Developer Kotlin | 𝐑𝐞𝐚𝐜𝐭 𝐍𝐚𝐭𝐢𝐯𝐞 | 𝐅𝐥𝐮𝐭𝐭𝐞𝐫 | 𝟖+ 𝐘𝐞𝐚𝐫𝐬
I’m a Mobile App Developer focused on building scalable, secure, and production-ready mobile products for iOS and Android ecosystems. My work combines mobile app development, mobile app design, clean architecture, API integrations, Firebase workflows, authentication, analytics, payments, push notifications, and long-term product support. I focus not only on features, but also on performance, stability, maintainability, and business growth.
As an iOS App Developer Swift specialist, I deliver native Apple ecosystem solutions through Swift, ios development, ios mobile app development, ios swift engineering, App Store readiness, watchos, apple watch, watchkit, and smart watch integrations. My iOS experience covers MVPs, product recovery, scalable production systems, enterprise apps, and secure ios applications. As an iOS App Developer Swift expert, I focus on polished UI, reliable architecture, optimized performance, and maintainable code.
As an Android App Developer Kotlin specialist, I build native Android apps using Kotlin, android app development, android development, modular architecture, Firebase, APIs, payments, analytics, authentication, and production-ready release workflows. My Android App Developer Kotlin work includes scalable android app, android app developer, android application, and complex mobile ecosystems designed for long-term growth. As an Android App Developer Kotlin expert, I focus on clean architecture, stable performance, security, and maintainable Android products.
I work as an iOS App Developer Swift and Android App Developer Kotlin for businesses that need reliable native mobile development, strong technical decisions, and product-focused delivery. This native expertise helps create secure ios and android solutions for fintech, e-commerce, booking platforms, fitness, health, taxi, transportation, delivery, dating apps, social media app, live streaming app, video streaming systems, AI-based mobile systems, SaaS, business apps, wearables, and IoT.
When product goals require faster launch or flexible delivery, I also support react native mobile, react native developer, react native expert, react native app, react developer, react js, react redux, react node, react native firebase, cross platform mobile development, cross platform mobile, hybrid app, hybrid app developer, flutter, flutter developer, flutter dart, flutter firebase, and flutter app workflows.
⭐️⭐️⭐️⭐️⭐️
“Reliable mobile app developer delivering stable releases. From MVP recovery to scalable production systems.”
🎯 What I bring:
✔️ 8+ years as a mobile app developer across full mobile app development lifecycles.
✔️ Strong iOS App Developer Swift background for native ios app, ios developer, senior ios developer, ios app developer, and scalable swift ios development.
✔️ Strong Android App Developer Kotlin background for native android developer work, kotlin developer workflows, android app development, and enterprise Android delivery.
✔️ Experience with API integrations, Firebase, authentication, analytics, payments, push notifications, backend coordination, wordpress, shopify, and mobile app marketing.
✔️ Product collaboration with mobile app designer, mobile app developers, product teams, and business stakeholders.
📱 Mobile Applications I Develop:
• Taxi & Transportation Apps
• Booking platforms
• Fitness & Health Apps
• AI-based mobile systems
• Security-focused ios and android solutions
• Fintech & Payments Apps
• E-commerce apps connected with wordpress and shopify
• Business & SaaS applications
• Social media app, live streaming app, and video streaming platforms
• Wearables & IoT systems with watchos, apple watch, watchkit, and smart watch
• Delivery and Dating Apps
🚀 Technologies & Skills
I architect scalable ecosystems combining native and cross-platform engineering. iOS App Developer Swift products are powered by Swift, ios developer swift workflows, ios development, ios swift delivery, App Store readiness, and iOS App Developer Swift expertise. Android App Developer Kotlin products are powered by Kotlin, android application architecture, Firebase, API connectivity, and Android App Developer Kotlin expertise. I also deliver react native, flutter, hybrid app, and cross platform mobile ecosystems.
As an iOS App Developer Swift professional, I help teams build polished iOS applications that are easy to scale. With both iOS App Developer Swift and Android App Developer Kotlin expertise, I support full-cycle mobile app development. iOS App Developer Swift and Android App Developer Kotlin delivery stays production-focused.
📩 Ping me. Let’s build something great.
Eugene Z.
has worked
.
Associated with
Natife Mobile
$700K+
earned
$55/hr
97%
Job Success
$1M+ earned
Available now
Offers consultations
Start of list.
End of list.
About Me
I have 25+ years of experience in partial CTO, CEO, Mobile App Development Project Management, specializing in Android, iOS, & Cross-Platform App Development using Java, Kotlin, Swift, Objective C, React Native, Redux Flutter, Firebase, Mongo Db, User Authentication, EHR, FHIR, HL7, HIPAA compliance, Typescripts, and AI-driven applications.
My expertise spans iOS & Android development, AI-powered solutions, seamless authentication systems, and full-stack capabilities, ensuring modern, high-performance apps for businesses of all sizes.
Our Agency
Since July 2017, my wife, our talented 55+ team members, and I have been delivering world-class digital solutions.
- 150+ apps successfully delivered across multiple platforms in the last year
- $4M+ turnover on Upwork
- 500+ successful projects, 15,000+ hours worked
- Close to a 100% success rate
- Worked with 7, 8, and 9-figure businesses
Our Expertise
Mobile App Development
• Android, iOS, & Cross-Platform Apps (Java, Kotlin, Swift, Objective C, React Native, Flutter)
Web & Full Stack Development
• Front-End: React.js, Angular.js, Next.js, WebRTC
• Back-End: Node.js, Firebase, MongoDB, PostgreSQL
• Cloud Deployment & API Integrations
E-commerce & CMS Development
• Shopify Developer & Customization
• WordPress Developer & WooCommerce Solutions
UI/UX Design & Branding
• Adobe XD, Figma, Photoshop, Sketch
Digital Growth & Security
• SEO & Digital Marketing Optimization
• Data Security & Intellectual Property Protection
Intellectual Property Services
• Trademark & Copyright Assistance
Why Choose SolidAppMaker?
- Tailored Approach: Every project is customized to fit your needs and budget.
- Agile Workflow: Regular updates, milestones, and transparent communication.
- High-Quality Development: Rigorous testing & performance optimization.
- Competitive Pricing: Top-tier services at fair and transparent pricing.
- Proven Track Record: Experience with MVPs, SaaS platforms, AI-driven apps, and enterprise solutions.
Why SolidAppMaker Stands Out
- 8+ years of expertise in UI/UX, mobile apps, SaaS & web development
- 510+ projects successfully completed for startups & enterprises
- 10+ awards & recognitions, featured on Upwork & top design platforms
- 50+ countries served, delivering top-tier prototyping & development solutions
Proven Results:
- SaaS UI/UX enhancements boosted retention by 60%
- Mobile UI redesigns reduced churn by 40%
- Web App UX improvements increased task completion by 90%
- eCommerce UI revamps increased sales by 70%
Industries We Cover
Healthcare, Transport, Retail, Asset Management, Real Estate, Dating, Nature/Wildlife, Rental, Food Delivery, Fintech / Finance and Banking, Cryptocurrency, Entertainment, Hospitality, Logistics, Manufacturing, Media and Publishing, Non-Profit, Sports and Fitness, Travel and Tourism, Utilities, Wellness, Medical Dashboard, Marketplace, Advertising, Automotive, Business Innovations, Ecology, Human Resources, LegalTech, Lifestyle, Fashion, Marketing, Navigation, Education, E-learning.
Highlighted Skills
Project Planning, MVC Architecture and RESTful APIs, Front-end Technologies (React.js, HTML5, CSS3, JavaScript), Responsive and Mobile-first Design, Database Design and Implementation (MongoDB, Firebase), User Authentication, Integration of Third-party APIs, Deployment to Cloud Platforms (AWS), Test-driven Development, Agile Methodologies (Scrum, Kanban), Security Technologies, QR Code Scanner, GPS and Mapping, Blockchain and NFT, ChatGPT and Artificial Intelligence.
Flutter Developer 10+ years of experience
As a Mobile App Developer and Full Stack Developer with deep expertise in SaaS Mobile App, ReactNative App I bring over a decade of experience in building high-performance cross-platform mobile application.
As a talented Flutter Developer with good knowledge of cross-platform development, I specialize in crafting high-performance mobile apps for both iOS and Android platforms.
I made more than 400 apps using Flutter.
Flutter is my main tech stack, I helped dozens clients making top-performing apps using Flutter.
I am a dedicated mobile app developer with extensive experience building cross-platform apps in Flutter, React Native, and Expo. As a full stack developer, I combine clean front-end design with robust back-end systems using Laravel, Node.js, or Firebase to deliver high-performance mobile solutions. FlutterDeveloper MobileApp AndroidDevelopment IOSDeveloper.
Next Steps – Let’s Build Something Amazing!
📅 Would you be available for a 30-60 minute free consultation?
During this meeting, we will:
- Go over your project goals, technical needs, and budget.
- Provide a project plan with a timeline and cost estimate.
- Discuss the best development approach to fit your vision.
📩 Send me a message, and I’ll share the Upwork scheduler link so we can set up a time that works best for you.
Looking forward to collaborating and creating something extraordinary!
Best regards,
John H Fijen
John F.
has worked
.
Associated with
SolidAppMaker LLC
$1M+
earned
$18/hr
98%
Job Success
$300K+ earned
Start of list.
End of list.
I help startups and enterprises transform ideas into high-performance, scalable mobile applications that users love and businesses rely on.
With 10+ years of hands-on experience in iOS and Android development, I specialize in building secure, user-centric, and production-ready mobile apps from MVP to enterprise scale. My background in Agile project leadership ensures smooth execution, transparent communication, and on-time delivery.
Mobile Development Expertise
iOS Development
• Swift
• watchOS, SiriKit, HealthKit
• Apple Watch integrations
• App Store deployment & optimization
Android Development
• Kotlin
• Flutter & React Native (cross-platform)
• Google Play deployment
Wearables & IoT
• Fitbit, Garmin, Polar
• BLE (Bluetooth Low Energy) integrations
• Smart medical devices (BP monitors, Spirometers, Digital Stethoscopes)
Backend & Cloud Integration
• Node.js, PHP
• REST & SOAP APIs
• Firebase
• AWS & Azure cloud services
• Real-time systems (WebRTC, XMPP, VoIP)
• JSON / XML integrations
I ensure secure, scalable architecture aligned with HIPAA, GDPR, and PIPEDA compliance when handling sensitive user data.
Industry Experience
-HealthTech & Telehealth
-Femtech
-Women wellness
-Female Helathcare
-Fitness & Wellness Platforms
-Mental Health Apps
-PropTech Solutions
-FinTech Applications
-Workflow & Enterprise Systems (CRM, ERP, POS, Supply Chain)
-Multi-Vendor E-commerce & On-Demand Platforms
From custom workflow automation tools to large-scale consumer apps, I focus on performance, security, and seamless UX.
Tools & Workflow
• Agile (SCRUM, Kanban, Hybrid)
• JIRA, Trello
• GitHub, Bitbucket
• CI/CD & Version Control Best Practices
My Agile background allows me to manage development cycles efficiently, reduce technical debt, and maintain clarity between business goals and technical execution.
What You Can Expect Working With Me
-Clean, scalable, maintainable code
-Clear milestones & proactive communication
-Performance-optimized architecture
-Strict data security standards
-Long-term technical partnership mindset
If you’re looking for a reliable senior mobile developer who understands both technology and business impact, let’s build something powerful together.
less
Shubham S.
has worked
.
Associated with
Flexsin Technologies
$10M+
earned
$35/hr
100%
Job Success
$30K+ earned
Offers consultations
Start of list.
End of list.
Welcome to my profile! I’m glad you’re here.
For the past 9+ years, I’ve been building high-quality, native mobile applications using the best tools available: Swift / SwiftUI / Objective-C for iOS and Kotlin / Java / Jetpack Compose for Android. From sleek, simple apps to massive enterprise-level platforms with complex backend logic, real-time data, and multi-layered architecture — I’ve done it all.
Whether you need a beautifully designed iOS app, a lightning-fast Android product, or a full end-to-end solution that brings together frontend, backend, AI, and scalable infrastructure — I can take your idea and turn it into a polished, production-ready product.
🌟 What I Do
As a Native Mobile Developer, I specialize in building high-performance iOS and Android apps with strong attention to UI, UX, security, and smooth user experiences. I combine clean architecture patterns with robust backend logic to ensure everything works flawlessly across all devices — smartphones, tablets, smartwatches, Apple TV, and even Android TV.
I work with REST APIs, GraphQL, Firebase, Firestore, WebSockets, on-device ML, and advanced mobile architecture patterns to deliver fast, intuitive, and scalable apps.
🚀 Need help with your mobile app? You're absolutely in the right place.
1️⃣ Deep Expertise in Mobile App Development 📱
I collaborate with a strong engineering team of 50+ specialists, delivering full-cycle mobile app development — from idea validation and prototyping to UI/UX, backend architecture, QA testing, store deployment, and long-term support.
We build:
- Native iOS apps (Swift, SwiftUI, Objective-C)
- Native Android apps (Kotlin, Java, Jetpack Compose)
- Cross-platform apps (Flutter, React Native, KMM)
- Custom backend systems
- AI-powered mobile features and automation tools
Whether you’re building an MVP or scaling a mature product — we’ve got you covered.
2️⃣ Accelerated Time to Market ⏱⚡
- We deliver apps 30–50% faster than most teams thanks to:
- Agile workflows (Scrum/Kanban)
- CI/CD automation
- Reusable architecture patterns
- Parallel development (iOS + Android + backend)
- Faster launch = stronger competitive advantage.
3️⃣ Expert Mobile Technologies 🛠️
- Swift, SwiftUI, Objective-C
- Kotlin, Java, Jetpack Compose
- Flutter, Dart
- React Native, TypeScript
- Firebase, Firestore, AWS, Node.js, Python, Django
- AI/ML integrations
Performance, responsiveness, clean code — no compromises.
4️⃣ Exceptional UI/UX Interfaces 🎨
- As a mobile UI/UX designer, I create:
- Elegant iOS & Android app designs
- Smooth animations (SpriteKit, Lottie)
- Pixel-perfect layouts
- Intuitive flows aligned with user psychology
- Brand-consistent visuals (logo design, branding, Illustrator work)
We design with purpose — not just pretty screens.
5️⃣ Scalable Back-End Architecture 🗄️
Your backend is the backbone.
Our backend expertise includes:
- Node.js, TypeScript
- Django, Python
- Laravel, PHP
- GraphQL & REST APIs
- AWS / GCP / Azure / Serverless
- Firestore, SQL, NoSQL
We ensure flawless performance, even under heavy load.
6️⃣ AI-Powered Mobile Applications 🤖
I integrate:
- ChatGPT & LLMs
- Custom ML models
- Recommendation engines
- Predictive analytics
- Computer vision tools
- Voice & NLP processing
Your app becomes smarter, more personal, and more efficient.
💼 Tech Stack Overview
Android: Kotlin, Java, Jetpack Compose, Android Studio
iOS: Swift, Objective-C, SwiftUI, RxSwift
Cross-Platform: Flutter, Dart, React Native, KMM
Backend: JavaScript/TypeScript, Node.js, Django, Python, GraphQL, REST API, AWS, SQL
Frontend: React, Redux, Vue, MUI, Vuetify
Also: branding, UI/UX, DevOps, CI/CD, QA testing, and store publishing.
Highlighted Skills
android, android developer, android kotlin, android app, reverse engineering (android), android tv app, android/ios smartphone apps, ios, ios developer, ios app, ios ui design, ios marketing, swift, swiftui, app developer, mobile app development, mobile app design, mobile ui ux designer, mobile game developer, cross-platform mobile development, hybrid app development, react, react developer, react native, react native mobile, react typescript, frontend react, backend, backend developer, node, javascript, typescript, firebase, firestore, firebase analytics, react + firebase, python, python developer, machine learning, data scientist, django, kotlin, kotlin developer, kotlin android, kotlin multiplatform, java, flutter, jetpack compose, compose (android), full stack developer, web developer, web design, web designer, branding, logo design, illustrator, wordpress, shopify, laravel, blockchain, apple watch, watchkit, spritekit, watchOS development, tv app, qa testing, app tester, ceros, synology, semrush, upload products
💬 Feel free to message me here on Upwork —
I’ll be happy to discuss your project, suggest solutions, and help you bring your vision to life.
Regards, Valerii
📆 Last Updated: 12/15/2025
Valerii S.
has worked
.
$50/hr
100%
Job Success
$200K+ earned
Available now
Offers consultations
Start of list.
End of list.
⚡ 14-Day MVP Delivery – Your production-ready mobile app launched in 2 weeks, not 2 months
🏆 Former Apple iOS Engineer – Silicon Valley standards meet startup speed for investor-ready applications
📱 70+ Apps Launched – Proven track record turning founder ideas into funded businesses on iOS and Android
Need Expert Mobile App Development That Actually Delivers on Time?
I'm a former Apple iOS engineer offering professional mobile app development for startup founders who need results fast. While other mobile app development agencies take 3-6 months and disappear mid-project, I deliver market-ready MVPs in 14 days or less. No crashes. No excuses. No communication gaps.
I've successfully launched 70+ applications across the iOS App Store and Google Play Store through strategic mobile app development. But here's what matters more: I've helped multiple founders turn their ideas into investor-ready apps that secured real funding. One client came to me after their previous mobile app development team ghosted them 3 months into the project. They had an investor meeting in 2 weeks and nothing to show. I rebuilt their entire native app from scratch in 13 days using React Native. The app worked flawlessly in their pitch. They closed $500K in seed funding.
That's the difference between a developer who codes and a developer who understands your real goal isn't just an app – it's launching your business before competitors beat you to market. I use test-driven mobile app development methodology with enterprise-grade architecture, so your app doesn't just work on day one. It scales as your business grows. You get weekly progress builds for continuous feedback, and I respond to messages within hours, not days. No more chasing developers who went silent.
Whether you need iOS development, Flutter development, or cross-platform solutions with React Native, my mobile app development services deliver apps that look professional, function perfectly, and stay within your budget. No surprise costs. No endless revisions. Just a clear timeline and a finished product that's ready to make you money.
Mobile App Development Services:
- iOS App Development (Swift, native iOS development)
- React Native Development (cross-platform iOS & Android apps)
- Flutter Development (modern, scalable mobile applications)
- MVP Development (investor-ready apps in 14 days)
- Mobile App Design (professional UI/UX that converts)
- App Store & Google Play Deployment (end-to-end launch support)
Ready to Launch Your App Fast?
If you're tired of mobile app development projects that drag on for months, developers who disappear, or apps that crash when you need them most – let's talk. Send me a message with your project details, and I'll show you exactly how my proven mobile app development process can get your app built, tested, and launched in 14 days. Every successful mobile app development project starts with a conversation. Your competitors aren't waiting. Neither should you.
Sagar M.
has worked
.
Associated with
BrewApps LLC.
$35/hr
96%
Job Success
$200K+ earned
Available now
Offers consultations
Start of list.
End of list.
🏆 𝗧𝗢𝗣 𝗥𝗔𝗧𝗘𝗗 𝗣𝗟𝗨𝗦 🏆
✅ Mobile App Developer 7+ years of experience
✅ SaaS Mobile App Developer 5+ years
✅ 35 mobile app development jobs completed successfully
✅ Android and iOS Mobile Expert
✅ Built 27+ UX-first Mobile App development jobs for 22 companies
✅ On-Time and Cost-Effective Delivery
✅ Future-Proof Solutions Showing a Minimum 41% ROI
✅ 4354 mobile app development hours on Upwork and still counting
✅ 100% Job Success in mobile app development (Client Satisfaction Ratio)
✅ 98% of Clients Recommended working with me
✅ 80% Long-term Repeat Clients
✅ 7+ years of experience in mobile app development, 6 years experience in iOS mobile app development, 7 years experience in Swift and Kotlin, 4 years experience in Flutter, React Native, 2 years experience in KMM, KMP
Full stack mobile app developer and mobile app UI UX designer with 7+ years of experience in Mobile App Development, specializing in iOS, Swift, Android, Kotlin, KMM, Kotlin Mutliplatform / KMP, React Native, and Flutter. I have successfully delivered 120+ mobile applications in different roles as mobile app developer, flutter app developer, flutter full stack developer, flutter flow, mobile app design, mobile ui ux designer, swift ios developer, android developer, kotlin developer, react native developer, mobile game developer achieving a 5-star rating on Upwork and helping clients scale their businesses with high-performance solutions.
Apart from mobile app development, I specialize in Mobile App Design for both iOS and Android, as well as Web App Design for SaaS platforms. My expertise extends to Interaction Design, User Flow Design, and creating seamless User Experience (UX Design) and User Interface (UI Design).
I follow a Design Thinking approach, ensuring every solution is user-centered and problem-solving. My process includes UI/UX Wireframing, Prototyping, and building Style Guides or UI-kits for consistent branding. I perform Design Audits and Design QA to maintain high standards across all projects.
🛠️ Design Tools:
My designs come to life through powerful tools like Figma, Zeplin, and InVision for prototyping and collaboration. I leverage Adobe Illustrator, Adobe Photoshop, and Adobe XD for detailed visual design. For complex wireframes and flow mapping, I turn to Axure, Sketch, and Balsamiq.
I also use Miro and Abstract for brainstorming and version control, while project communication and management happen in Slack and Jira.
Our Expertise at a Glance
• Mobile App Development: Android, iOS, & Cross-Platform App Development using Java, Kotlin, Swift, Objective C, Flutter, and more.
• Website and Full Stack Development: Crafting seamless back-end experiences with .Net, Python, Java, Javascript, React.js, Angular.js, Node.js, MERN, MongoDB, PHP, etc.
• Logo & UI/UX Design: Bringing your ideas to life with Adobe XD, Photoshop, Sketch, Figma, etc.
• End-to-End Solutions: From logo design, UI/UX development, workflow setup, testing to deployment in app stores, we've got it all covered.
We do not use v0.dev lovable.app CursorAI, Cursor, Windsurf, Trae, GitHub Copilot, Tabnine, Qodo, Devin AI, and AutoDev for speed up coding, we know other methods to do it efficiently.
We offer a comprehensive range of development services across mobile, web, and cloud platforms. Our mobile app development expertise includes building Android and iOS applications using technologies such as Flutter, Swift, Objective-C, React Native, and Xamarin, optimized for both smartphones and tablets with a focus on cross-platform compatibility.
In website and full stack development, we work with .NET technologies, including full stack .NET development, .NET Core, and Python with Django. Our team is experienced in developing both backend systems and user-friendly, responsive web interfaces, as well as working with various CMS platforms.
Our DevOps and DevSecOps capabilities cover cloud infrastructure and automation, leveraging tools like AWS, Azure, Docker, Kubernetes, GitLab CI, Ansible, and Terraform to build secure and scalable deployment environments.
We also build cross-platform and web applications using frameworks like Three.js and design tools such as Webflow, creating visually engaging and functional user experiences across devices.
Additionally, we are well-versed in integration and automation tools, including WebSockets, data integration, the ABP Framework, Discord API, and Autotask, allowing us to create seamless connectivity and workflow automation between systems.
Talent
Good Knowledge, Talented, Experienced, Skilled, Strong Experience, Proven Experience, Agency, Team, Company, Specialist, Proven Track Record, Strong Background, Write Clean Code, Deep Expertise, Bring to Life, Cross-platform, Attention to Detail, Long Term.
⚡️ AVAILABLE FOR NEW PROJECTS
⚠️ Press Invite Button on my page and let's talk.
Roman P.
has worked
.
Associated with
Itexus LLC 💚
$1M+
earned
$16/hr
100%
Job Success
$300K+ earned
Available now
Offers consultations
Start of list.
End of list.
Are you looking for a Mobile app developer who can design and develop your app for the next millions of users?
ARE YOU
- Looking for a mobile app development service starting from the design, development to release and publish a mobile app to Play Store and App Store for mobile app users/customers.
- Looking for a mobile app developer who can integrate new features into your existing Android app, iOS app or Flutter app based projects?
- Individual | Big company | Startup who wants to build and create Android app or iOS app from scratch?
- Looking for a mobile app developer who can transform your idea into reality?
- Someone who invests in the best so you get better results?
If any of that is what you need, message me and I am here to help you.
Who am I?
- I'm Sagarkumar Surani, a Senior Mobile App Developer with 10+ years of experience and a Master’s degree in Computer Science and Engineering.
- I worked with big brands, startups and individuals to create mobile apps for their requirements. My work also got featured a few times in the market store. Apps developed by me have 100 million+ downloads on store and users love to keep the app on their phone as a permanent app.
- I’ve worked with clients from over 40 countries, such as the USA, UK, Germany, India, and Australia, which has given me a strong understanding of different international markets. My experience covers a variety of industries, including Travel and Tourism, train ticket booking, transport, educational, hospitality, health & wellness, real estate, live streaming, Marketplace, food & delivery, human resources, fitness, financial & banking sectors, e-commerce, dating, sports, Betting, music/audio, and automotive.
I specialize in these high-quality Mobile App Design and Development areas:
- Android app development
- Kotlin, Java, Android SDK, Android Studio
- iPhone app development
- Swift, SwiftUI, Objective C, iOS SDK, Xcode
- Backend Development | Node.js
- Cross Platform Mobile App Development using Flutter, Dart
- UI/UX: Mobile design
- Mobile & Web app design
- UX/UI design
- Landing page design
Skills :
- Have experience developing, releasing & maintaining applications as a Mobile app developer
- Strong skills in executing pixel & animation perfect UI's relative to good app performance
- Have great communication skills and ability to work with your team
- Have a great understanding of MVC, MVP, MVVM and take great care to ensure each project is well-architecture with best practices and easily maintainable so it can be enhanced as feature grows.
- The ability to take initiative and work independently with very little supervision
- Application requirement analysis
- Translating requirements to technical languages
In addition to Mobile app development services, my topic areas of expertise include:
- Mobile Application Architect
- Native Mobile Application Development consultation
- Mobile Application UI/UX design using Figma, Adobe XD
- Mobile Application backend services Firebase, AWS Mobile Hub
- Mobile Application backend development: Node, Express, TypeScript, JavaScript, MongoDB, MySQL, PHP, RESTful API development, Google App Engine
- Website development, Web Scraping, Web Admin Panel, CMS Development
- Chatbot development, Facebook Messenger
If you still think this is right for you, contact me.
Thank you in advance for your time and consideration.
Kind Regards
Sagarkumar Surani
P.S.
- When you work with me your satisfaction is 100% guaranteed.
- Every person who ever worked with me got results. EVER!
- Even if you don’t hire me now, keep my profile link in case you need a Mobile App Developer later.
FAQ
Q: Can you provide maintenance support after development?
A: Yes, I provide free of cost maintenance support for 12 months after mobile app development.
Q: Can you help with Mobile app design?
A: Yes, I offer a Mobile app UX design as an additional service.
Q: Can you help with the landing page website for my mobile app product?
A: Yes, I can help to build the landing page for a mobile app product.
Warmly,
Sagarkumar Surani
-----------------------------------------------------
Native Android App Developer, iOS App Developer, Cross-Platform Flutter App Developer, Top Flutter Developer, React Native, Hire Best MERN Stack Developer, RESTful API Developer, API Integration, Frontend Developer, React.js, Backend Developer, Nodejs, Javascript, Figma, UI/UX Design, Prototype, In-app purchases, Location, Payment Gateway Integration, Apple Xcode, Android Studio, Push notifications, User authentication, User profile creation, QA, Unit Testing, Regression Testing, Dating App, Ecommerce App, RevenueCat, Adapty, 3rd Party SDK Integration, SQLite, MySQL, Firebase Cloud Firestore, Realtime Database, Kotlin, Swift, Java, Dart, SwiftUI, Twilio, Mapbox, HealthKit, Google Analytics, Amazon Web Services, DigitalOcean, Core Data, UIKit, MapKit, Phone, Full Stack Developer, iPad, OpenAI ChatGPT LLM, ChatGPT API Integration
.
Sagarkumar S.
has worked
.
$40/hr
100%
Job Success
$400K+ earned
Available now
Offers consultations
Start of list.
End of list.
🥇 𝐓𝐨𝐩 𝟏% 𝐓𝐚𝐥𝐞𝐧𝐭 - 𝐄𝐱𝐩𝐞𝐫𝐭 𝐕𝐞𝐭𝐭𝐞𝐝 on Upwork. I help startups and product teams build fast, clean, and scalable mobile apps. 👨💻 As a senior full stack developer with over 15 years of experience, I build apps that help startups and businesses grow.
🔧 𝐖𝐡𝐚𝐭 𝐈 𝐃𝐨
- Mobile Apps (iOS + Android): 40+ apps delivered. 25+ published to the App Store (⭐ 4.7 avg). Performance optimized, CI/CD deployed, built to scale.
- IoT & BLE: Deep expertise with ESP32, custom firmware, Bluetooth, and AWS IoT. Smart devices, real-time sync, low-latency control.
- AI/ML Integration: ChatGPT, ML models, and automation embedded into mobile/web apps. 5+ AI chatbots, 4 ML features built.
- Web Backend + Frontend: Full-stack engineer using Node.js, React, Laravel, MySQL. Solid APIs, fast UIs, maintainable code.
📱 𝐑𝐞𝐜𝐞𝐧𝐭 𝐖𝐨𝐫𝐤
- BLE-based TV Lift Controller: IoT app + firmware. 99.9% uptime. Reduced support tickets by 85%.
- Fitness Social Platform (Flutter): Scaled to 50K+ users. 40% MoM growth.
- QSR Ops Platform: Internal tool for 200+ fast food locations (Taco Bell, KFC, etc). Saved $1.2M/yr in ops cost.
- Sports Team App: Booking, scheduling, payments. Now used by 15K+ hockey players.
🧰 𝐒𝐭𝐚𝐜𝐤
Mobile: Flutter, Dart, React Native, Swift
Web: React.js, Node.js, Laravel
IoT: BLE, ESP32, Arduino, AWS IoT
AI: Python, OpenAI API, TensorFlow
DevOps: CI/CD, GitHub Actions, Docker
Tools: Figma, Postman, Firebase, MySQL
✅ 𝐖𝐡𝐲 𝐌𝐞?
- Built MVPs and scaled platforms — not just code, real products
- Own the process — architecture to deployment
- Communicate clearly
- Proactive
- Detail-oriented
Serhii O.
has worked
.
Associated with
Otrofy Inc. 🥇 Design, Develop and Deliver 🚀 Enterprise & Startups | iOS, Android | Mobile App and Web Development Agency Company
$1M+
earned