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Mobile developer with 14 years experience, 80+ shipped apps and more than 1M+ downloads. If you're starting a Flutter app from scratch, I take it from concept to the App Store. If your iOS or Android app has stalled, I get it shipping again. If a previous mobile app developer missed what you actually needed, that's where I usually come in. 𝗪𝗵𝗮𝘁 𝘆𝗼𝘂 𝗴𝗲𝘁 I work primarily in Flutter for smartphone apps, with native iOS and Android experience dating back to 2012. When backend or AI work is heavy, Python and Node.js handle it. Mobile app design happens early by a dedicated mobile app designer. 𝗪𝗵𝗮𝘁 𝟴𝟬+ 𝗮𝗽𝗽𝘀 𝘁𝗮𝘂𝗴𝗵𝘁 𝗺𝗲 Mobile app development starts with understanding the problem the product solves. A Flutter developer worth hiring flags problems before they become rebuilds. A few projects I've shipped as a mobile app developer: - Patient Gateway (UK) - Flutter app for medical transport with Firebase sync - Rheo (Switzerland) - Flutter app and PWA for vital signs via BLE biosensor - Inne Minilab (Germany) - fertility tracking with IoT BLE biosensor - ClosetBee (US) - Flutter AI wardrobe app, the kind of work I take on as an AI mobile app developer - MoveOn (Israel) - eco taxi app with route planning and payments - Warehouse App Set (UK, NDA) - 5 native apps for inventory and dispatch 𝗜𝗻𝗱𝘂𝘀𝘁𝗿𝗶𝗲𝘀 Healthcare, logistics, transportation, lifestyle, internal tools, AI integrations, fintech, travel, education. If you're looking for a mobile application developer or Flutter developer who thinks past the spec, that's the work I do. I've had clients reach out a year into a project after hiring the wrong mobile app developer first. Early hire saves months. Send a message with what you're building and I'll give a scope estimate and the first technical decision I'd want to settle. 𝗥𝗲𝗮𝗱𝘆 𝘄𝗵𝗲𝗻 𝘆𝗼𝘂 𝗮𝗿𝗲 Best, Stan --- - Experienced mobile app developer and experienced app developer with 80+ apps for iOS and Android since 2012, and 14 years as a mobile developer. - Senior mobile app developer leading architecture on every project, with MVPs launching in 8 to 12 weeks. - Senior Flutter developer with 20+ Flutter builds, first TestFlight usually in client hands by week 3. - Flutter app developer with user bases from a few thousand to 100,000+ monthly active. - iOS developer with 30+ apps published to the App Store and average ratings around 4.4 stars. - Senior iOS developer working in Swift with Objective-C and SwiftUI. - Senior iOS engineer shipping to iPhone, iPad, and Apple Watch with users in 15+ countries. - Android developer with 35+ Play Store apps across logistics, healthcare, and consumer categories. - Senior react native developer with a partner team with 30+ React Native apps and 5+ react native dev iterations on legacy code, plus mobile React and React developer logic across 3+ codebases for React native mobile app developer projects. - Full-stack developer running Node.js, Firebase, Supabase, and Python backends with APIs serving up to 100K+ requests per day. - Full stack developer process cuts bugs by ~60%. - Flutter mobile app developer work spans 25+ apps, including one Flutter app with 1M+ downloads on App Store. - Full-stack mobile app developer and web developer work covers dashboards cutting reporting time ~70% on 20+ projects, with Wordpress marketing sites alongside the mobile launch. - Native app development uses Swift for iOS work and Kotlin with Java for Android development. Hybrid app development uses Flutter and React Native. - iOS Development and Android App Development cover 65+ App Store and Play Store apps. - Backend runs in Laravel and Node.js with Python for AI, JavaScript and PHP for scripting. HTML and web design support webpages and admin panels. - API integration for payments, maps, auth. User profile creation is standard in every MVP. Mobile app bug fix work makes up roughly 20% of engagements. - Healthcare app development and healthcare SaaS development include data handling with HIPAA or GDPR compliance. Secure PHI handling and HL7 FHIR integration are standard. Rheo and Inne Minilab ship medical device BLE integration. Healthcare app developer engagements typically run 8 to 16 weeks. - Logistics app development covers real-time map integration, route planning, and inventory dispatch. Logistics app developer projects ship with offline sync and live tracking from day one. Flutter is my main stack, with 30+ Flutter projects shipped to production in the last four years. Flutter development treats mobile app performance as scope from day one. MVP mobile app development is where most projects start. App development quality matters most at MVP stage, and mobile app marketing readiness comes before launch. Where FlutterFlow fits the early phase, I work as a FlutterFlow developer compressing timeline by ~60%. Mobile app development FlutterFlow work happens when MVP is live but the team needs a Flutter developer to ship.

Top Rated Plus | $200K+ Earned on Upwork | 100% Job Success | 10+ Years on Upwork I'm an Android Developer and Mobile App Developer with 12+ years of professional experience and a PhD in Computer Science. With $200K+ earned, 100% Job Success, and Top Rated Plus status on Upwork for 10+ years, I build production-ready Android and mobile applications that scale, not MVPs that fall apart under real user traffic. As an Android Developer, my core work covers native Android App Development in Kotlin and Java, full-lifecycle delivery from requirements and architecture through Google Play release, and backend integration with REST APIs, Firebase, AWS, and third-party services. I've shipped apps with 1M+ downloads. As a Mobile App Developer, I also deliver cross-platform solutions using React Native and Flutter when a project needs iOS and Android from a single codebase. As an Android Developer and Mobile App Developer, I've delivered across fintech, healthcare, logistics, social networking, sports, e-commerce, fitness, and entertainment. I also have extensive experience in healthcare and safety applications where data encryption, secure messaging, and compliance are non-negotiable. My architecture approach as an Android Developer is Clean Architecture with MVVM and MVP patterns, Kotlin Coroutines and Flow for async tasks, Hilt for dependency injection, and Jetpack Compose for modern UI. I use RxJava where legacy codebases require it and maintain CI/CD pipelines with Jenkins and TeamCity to keep releases reliable and predictable. As a Mobile App Developer and Kotlin developer, I take ownership of API planning with backend teams, code reviews, refactoring, and full technical documentation so the codebase remains maintainable long after delivery. I work as part of a team at Requestum, which means I can bring in backend, iOS, or QA specialists when a project needs more than one mobile app developer to ship on time. Clients typically work with me when they need: - an Android Developer to build a native Kotlin app from scratch to Google Play release - a Mobile App Developer to deliver iOS and Android from a single React Native or Flutter codebase - an Android App Developer to refactor, optimize, or extend an existing Kotlin or Java codebase - a Kotlin developer who understands Clean Architecture and can own the full technical roadmap - a mobile app developer with experience in fintech, healthcare, logistics, or social platforms If you need an Android Developer who ships production-grade apps and takes full technical ownership, let's talk. Main stack: Kotlin, Java, Android SDK, Jetpack Compose, Android Jetpack, Hilt, Kotlin Coroutines, RxJava, Retrofit, Firebase, AWS, Google Maps API, Stripe, React Native, Flutter, Room, Realm, Jenkins, Docker.

I'm an Android Developer / Mobile Developer with 10 years of experience helping small businesses and startups translate their vision into scalable, high-performance apps from 0 to launch using the latest technologies ( Kotlin , Coroutines , Jetpack Compose , Jetpack libraries , Kotlin Multiplatform ). I specialize in: - on-device AI integration using MediaPipe / TFLite / Google ML Kit (Object detecton , Face and pose detection , Text summarizing / OCR , text-to-speech , speech-to-text , etc.); - building media, social, and everyday tools (not games); - fixing app performance , memory leaks , crashes and ANRs , especially in complex or “vibe-coded” apps. 🌟🌟🌟🌟🌟 Recent feedback : "I was particularly impressed by his strong attention to detail — nothing was overlooked, and the quality of the work consistently met high standards. He showed real commitment to the project, staying engaged and proactive throughout the development process. His regularity and consistency in delivering work made collaboration smooth and reliable." - Neil 🚀 Also I've been building my own Android apps so that gives me a deep understanding of not only a technical part but also ASO and monetization strategy. ✅️ Recent large-scale projects: --- PDF Maker & Reader (130k+ installs , 🌟4.6 on Google Play) Role: Android Developer / Android App Developer / Kotlin Developer I recently built this high-performance Android app from scratch based on Figma mockup using Kotlin. It allows users to quickly convert images to PDF and edit existing PDFs using a fast, local-first architecture. The app has achieved 130k+ downloads and 8k monthly active users on Google Play, with the crash rate lower than 0.1%. --- --- US Medical Education App (COMQUEST for COMLEX & COMAT Prep) Role: Android Developer / Android App Developer / Mobile Developer As part of an international team alongside iOS Developer and Web Developer, I built this Android app from scratch based on Figma designs for US medical students. Continue providing ongoing support for this project, ensuring the mobile app remains a stable and reliable tool for users. --- --- US Automotive Video Suite app Role: Android Developer / Android App Developer / Mobile Developer In collaborating with an iOS Developer and a Full Stack Developer, I built two native Android apps from scratch as a clone of iOS apps (Dealer Video Inventory and Dealer Video Suite) that allows dealers to capture high-quality vehicle inventory videos and photos. These projects helps dealers increase sales through personalized video. --- 🌟 🌟🌟🌟🌟 "Dmitri is a pleasure to work with. He's Android programming skills are exceptional. He's always professional and easy to work with. He is very methodical in his approach. Which at times has resulted in delivery scheduling slipping a little but I rather have a good product than a hastily put together product. We're continuing to work with Dima for other projects." - Philip Whether you are looking for a Mobile Developer to lead a new project or an Android Developer to optimize an existing Java / Kotlin codebase or optimize performance, my goal is to provide technical clarity and long-term stability. As a team player for cross-platform projects I have a proven track record of working alongside iOS developers to ensure smooth releases. I also have specific experience collaborating with Flutter Developers and Full Stack Developers to bridge the gap between cross-platform Flutter / React Native code and the system features specifically by developing custom Java / Kotlin modules to handle native Android OS functionality that standard Flutter plugins can't reach. --- 🚀 My core stack: 🔸️Languages: Java , Kotlin 🔸️UI: XML , Jetpack Compose 🔸️Architecture: MVVM , MVI , Clean Architecture 🔸️Native: Android SDK , Android Studio 🔸️Multiplatform: Kotlin Multiplatform ( KMM / KMP ) / Compose Multiplatform ( CMP ) 🔸️Key features: Camera , Photo & Video capture and edit using FFMpeg , OpenGL , OpenCV ; GPS , Location , Chat , Background syncronization , WorkManager and foreground services, ofline-first approach, on-device AI / LLM , VPN / WireGuard , ExoPlayer / Media3 🔸️On-device AI integration : Video analysis , Image recognition , Object detection , Face detection , Pose Detection , Camera stream analysis , Text-to-Speech , Speech-to-Text ( MediaPipe / Google AI Edge , TensorFlow / TFLite , Google ML kit ). 🔸️Cloud AI integration : OpenAI , Gemini API

Ready to collaborate as dedicated Android Kotlin engineer for comprehensive mobile development - reach out anytime and I can begin within 24 hours. I’m a senior Android developer with 9+ years of professional experience creating fast, reliable, and production-ready mobile applications. As an expert Android app developer, I specialize in Kotlin and Java to build native Android apps that deliver real business value and solve complex challenges. Whether you’re launching from zero or enhancing your existing Android application with advanced features, I deliver structured development, architectural clarity, and clean mobile solutions. 🔧 What I bring to your Android project: ✅ End-to-end Android app development - From initial planning through coding, testing, I manage the complete development cycle using proven Android development practices with Kotlin and Java. ✅ Scalable mobile products - I’ve transformed MVPs into mature, long-running applications using MVVM, MVI, and Clean Architecture. You get maintainable Android code built for sustained growth. ✅ Comprehensive testing approach - I build unit tests, UI automation, CI/CD pipelines, and automated test coverage to keep your Android app stable and reliable through every release. ✅ Hardware and GPS integration - BLE beacons, barcode scanners, Zebra SDK, GPS tracking systems, speech recognition, Google Maps integration, camera APIs, and Unity SDK are all in my core toolkit. ✅ Optimization and stability - optimization and monitoring with Firebase, Android Profiler, Sentry and custom analytics solutions. 📱 Types of Android apps I’ve built: ∙ GPS-enabled map applications with live location tracking and navigation ∙ Warehouse management apps with barcode scanning and inventory systems ∙ Kiosk applications for retail, hospitality, and self-service terminals ∙ Speech recognition and voice-to-text transcription applications ∙ Location-aware apps using BLE beacons and proximity detection ∙ Camera-focused tools for media capture and processing ∙ AI-powered conversational interfaces and productivity apps ∙ Unity-integrated experiences within native Android applications 🛠 Technology stack: Kotlin, Java, Android SDK, Jetpack Compose, GPS/Location Services, Google Maps SDK, Speech Recognition, RxJava, Coroutines, Dagger, Hilt, Koin, MVVM, MVI, Firebase, BLE, Unity, Zebra SDK, Git, Jenkins, Jira If you need a dependable Android app developer with extensive Kotlin and Java expertise, proven mobile architecture skills, GPS and map integration experience, and a track record delivering warehouse, kiosk, and enterprise mobile solutions - I’m ready to contribute. 📩 Let’s build something robust, scalable, and engineered to last.

$𝟑𝟎𝐊+ 𝐢𝐧 𝐂𝐥𝐢𝐞𝐧𝐭 𝐑𝐞𝐯𝐞𝐧𝐮𝐞 | 𝟑𝟎+ 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬 | 𝟏𝟎𝟎% 𝐂𝐥𝐢𝐞𝐧𝐭 𝐒𝐚𝐭𝐢𝐬𝐟𝐚𝐜𝐭𝐢𝐨𝐧 My goal is simple - your mobile app should be stable, scalable, and valuable for your business. I’m Olha, a Mobile App Developer specializing in native iOS and Android development with Swift, SwiftUI, Kotlin, and Java. I help startups, SaaS companies, healthcare products, fintech platforms, logistics businesses, streaming services, and enterprise teams build mobile applications that are ready for real users. Whether you need an MVP, a new mobile app from scratch, improvements to an existing iOS or Android app, or long-term mobile development support I can help you move from idea to launch with clean native development. ✔️ Mobile App Developer — full-cycle mobile app development from idea, architecture, and development to App Store and Google Play release. ✔️ iOS Developer — native iOS apps built with Swift, SwiftUI, Objective-C, Apple frameworks, and scalable architecture. ✔️ Android Developer — native Android apps built with Kotlin, Java, Android Studio, Google SDKs, and clean maintainable code. ✔️ Native iOS & Android Development — stable, fast, and user-friendly mobile apps without unnecessary cross-platform complexity. ✔️ Long-Term Mobile Development Partner — support, maintenance, new features, performance optimization, and product scaling after launch. 🔥 ACHIEVEMENTS ✔️ 8+ years of experience as a Mobile App Developer building native iOS and Android applications across multiple industries. ✔️ 30+ mobile app development projects delivered for startups, SaaS, healthcare, fintech, logistics, streaming, wellness, and enterprise products. ✔️ $30K+ in client revenue supported through mobile app development, product improvements, and long-term development cooperation. ✔️ Native mobile apps built for products with 2M+ downloads, 500K+ users, and high daily engagement. ✔️ iOS and Android applications delivered for logistics platforms operating across 60+ cities. ✔️ Mobile app development for AI-powered platforms, fintech products, wearable apps, booking systems, delivery apps, and streaming solutions. ✔️ Strong experience improving existing iOS and Android apps through performance optimization, UI/UX improvements, bug fixing, and feature development. 🚚 WHERE I DELIVER ✔️ As a Mobile App Developer — I build mobile applications from MVP to production-ready product, including architecture, development, integrations, testing, deployment, and maintenance. ✔️ As an iOS Developer — I deliver native iOS apps for iPhone, iPad, Apple Watch, and Apple ecosystem products using Swift, SwiftUI, and Objective-C. ✔️ As an Android Developer — I deliver native Android apps for smartphones, tablets, WearOS devices, and Android-based ecosystems using Kotlin and Java. ✔️ As a Native Mobile App Developer — I work with Firebase, AWS, REST APIs, GraphQL, push notifications, subscriptions, analytics, payments, and real-time features. ✔️ As a long-term development partner — I help improve existing mobile apps, reduce technical debt, optimize performance, and add new features without breaking the product. 🏆 INDUSTRY IMPACT ✔️ Healthcare & Wellness Apps — native iOS and Android development for wellness platforms, healthcare tools, wearable integrations, biometric data, and user activity tracking. ✔️ Fintech Mobile Apps — secure payment flows, Stripe and PayPal integrations, Apple Wallet features, subscription systems, and financial dashboards. ✔️ Logistics & GPS Apps — GPS tracking, geofencing, delivery tracking, real-time location updates, driver apps, and logistics management tools. ✔️ Streaming & IPTV Apps — IPTV applications, OTT platforms, FireTV apps, video playback optimization, and low-latency streaming features. ✔️ Wearables & IoT Apps — Apple Watch, WearOS, BLE devices, IoT sensors, smart devices, and biometric integrations. ✔️ AI-Powered Mobile Apps — AI productivity apps, AI wellness platforms, LLM integrations, real-time analytics, and AI-powered user experiences. ✔️ Booking, Delivery & Marketplace Apps — mobile products with user profiles, payments, notifications, dashboards, real-time updates, and scalable app architecture. ⚒️ HOW I BUILD ✔️ iOS Development: Swift, SwiftUI, Objective-C, Xcode, Apple frameworks, Apple Watch, Apple Wallet, App Store deployment. ✔️ Android Development: Kotlin, Java, Android Studio, Google SDKs, WearOS, Google Play deployment, Android architecture. ✔️ Mobile App Development Stack: Firebase, AWS, REST APIs, GraphQL, push notifications, subscriptions, payments, analytics, dashboards, real-time tracking. ✔️ Product Development: MVP development, startup mobile app development, enterprise mobile apps, UI/UX optimization, performance improvements, feature development. ✔️ Architecture & Workflow: clean architecture, scalable codebase, CI/CD, Agile workflow, code review, app maintenance, long-term support.

I build AI-powered mobile apps that ship — from ChatGPT/LLM integration to on-device Core ML — for iOS, Flutter, and Android. Top Rated developer, 13+ years, 50+ production apps launched to the App Store and Google Play. I help startups and companies turn AI ideas into real, revenue-ready mobile apps — and I take them all the way from concept to the App Store. WHAT I DO I specialize in AI-powered mobile app development: integrating OpenAI (ChatGPT/GPT), Anthropic Claude, and other LLMs into native and cross-platform apps, plus on-device AI with Core ML, Vision, and Create ML. Whether you need an AI chatbot, an AI MVP, computer-vision features, voice/speech, or a RAG-powered assistant inside a polished mobile app, that's my core work. WHY CLIENTS HIRE ME 13+ years building mobile apps; 50+ production apps shipped Top Rated on Upwork, with a track record of full-cycle delivery I own the whole build: architecture, UI/UX, secure backend, App Store & Google Play launch Senior enough to advise on scope, cost, and the right AI approach before a line of code is written AI CAPABILITIES LLM integration: OpenAI API, Claude API, GPT models, function calling AI chatbots and AI agents; RAG with vector databases On-device AI: Core ML, ML Kit, TensorFlow Lite, Create ML Computer vision: image recognition, object detection, OCR NLP, sentiment analysis, recommendations, speech recognition MOBILE EXPERTISE Native iOS: Swift, SwiftUI, Objective-C, UIKit, Combine, Core Data Cross-platform: Flutter, React Native Android: Kotlin, Jetpack Compose, Java Backend & integrations: Firebase, AWS, GCP, REST/GraphQL, Node.js, Python Payments & subscriptions: Stripe, Apple Pay, Google Pay, In-App Purchases INDUSTRY EXPERIENCE Healthcare (telemedicine, patient tracking, AI diagnostics), fintech (payments, fraud detection, crypto wallets), fitness & wellness (activity tracking, AI coaching, nutrition), and e-commerce (personalized recommendations, AR try-on). HOW WE CAN START Book a paid consultation for technical advice and project scoping, or invite me to your project / send a message for a quick, complimentary exploratory chat about your app.