Hire the Best PhoneGap Developers

I develop high-performance hybrid mobile applications that deliver reliable results in real-world environments, including Firebase integrations, push notifications, custom native plugins, and complex SDK integrations. With 14+ years of experience and over 200 successfully delivered projects, I specialize in building, optimizing, and maintaining Android and iOS applications using Ionic, Cordova, Capacitor, Vue.js, and React Native. I help businesses launch scalable, cost-effective mobile solutions and solve critical issues that other developers struggle to fix. My expertise includes app stabilization, performance optimization, native SDK integration, App Store compliance, and troubleshooting complex mobile application challenges. ### What I Can Do for You ✔ Develop cross-platform mobile applications (Android & iOS) from scratch ✔ Convert existing websites or web applications into mobile apps ✔ Develop custom Cordova and Capacitor plugins ✔ Integrate native iOS and Android SDKs into Ionic applications ✔ Diagnose and resolve crashes, bugs, and performance bottlenecks ✔ Upgrade legacy applications (Cordova → Capacitor migration) ✔ Integrate APIs, Firebase services, and third-party platforms ✔ Resolve App Store and Google Play review and deployment issues ✔ Optimize application speed, stability, and user experience ### Technical Expertise • Ionic Framework (Angular & Vue) • Apache Cordova & Capacitor • Vue.js & React Native • JavaScript, TypeScript, HTML5, CSS3 • Native Android (Java/Kotlin) • Native iOS (Swift/Objective-C) • Firebase (Authentication, Firestore, Analytics, Push Notifications) • REST APIs & Third-Party Integrations • WebView Optimization & Plugin Debugging ### Specialized SDK & Plugin Development • Custom Cordova Plugin Development • Custom Capacitor Plugin Development • Native SDK Bridging for Ionic Applications • Microblink BlinkID Integration • Passport, Driver's License & ID Card Scanning • Selfie Verification & Face Matching • OCR & Document Data Extraction • Barcode & QR Code Scanning • Camera & Media Processing Integrations • Biometric Authentication • Payment Gateway SDK Integrations • Push Notification SDK Integrations One of my key specialties is developing custom native plugins for Ionic, Cordova, and Capacitor applications. I have successfully built and integrated complex SDKs, including Microblink BlinkID, enabling passport scanning, driver's license scanning, ID card recognition, selfie matching, and OCR-based data extraction on both Android and iOS. When a required SDK does not have an existing plugin, I can build the complete native bridge and integration from scratch. ### Why Clients Work With Me • Strong expertise in solving complex mobile application issues • Advanced debugging skills across native and hybrid environments • Extensive experience with plugin development and SDK integrations • Clear communication and reliable delivery • Proven track record with production-grade and long-term projects If your application is experiencing crashes, performance issues, SDK integration challenges, App Store rejections, or deployment problems, I can quickly identify the root cause and implement a reliable solution. From concept → development → deployment → scaling, I manage the complete mobile application lifecycle. Available to start immediately.

👋 Hi, I’m Oleksii - a Twilio expert with over 7 years of hands-on experience building scalable, real-time communication systems using the full Twilio stack: 📞 Programmable Voice / SMS, 🧠 TaskRouter & Flex, 🎛️ Studio, Functions, Conversations, Sync, Webhooks and more. I’ve successfully completed 120+ Twilio projects on Upwork, including: • Eliminating latency issues in phone calls 🔧 • Creating SMS marketing automation pipelines 📲 • Developing full-scale Flex dashboards with custom workflows 🧩 Clients describe me as: “Very skilled, excellent communicator, smart guy and a pleasure to deal with.” “Oleksii was very helpful and available :) We no longer have problems with latency during our phone calls.” 🛠 Whether you need help with: • Twilio Studio call flows • Complex webhook-based automation • TwiML, IVR, call forwarding setups • Integrating Twilio with CRMs or internal systems • Building voice/SMS logic in Node.js, Laravel, or Firebase environments …I’ve got you covered. Let’s bring your Twilio-powered solution to life 🚀 Feel free to invite me to your job or message me with questions.

I specialize in VoIP solutions with a focus on RingCentral (EX & CX) and Zoom (Phone & CC) project implementation and ongoing support. As a subject matter expert in the field, I work with businesses of all sizes to streamline communication systems, resolve complex technical challenges, and deliver seamless transitions to cloud-based telephony. Here's what you can expect when working with me: Deep Roots in VoIP: I'm not just certified; I'm passionate about what I do. With experience in RingCentral, Avaya, Zoom and Vonage, I'm well-versed in the intricacies of these platforms both in its UCaaS and CCaaS versions. Your Time Matters: I understand that every second counts in your business. That's why you can rely on me for prompt responses and effective solutions. Who I Serve: From small startups to large enterprises, I've had the privilege of assisting businesses of all sizes. My expertise spans various industries, including law firms, universities, fitness, and finance, to name a few. Here is a list of the most common tasks I perform within a VoIP platform: Call queues / Auto Attendant - IVR Call Forwarding / Call Routing Voicemail Setup / Custom Answering Rules Porting / User setup / Limited extensions SMS Automation** (10DLC) Multi Site Call logging expert / Audit trail Announcement / Audio greetings - Voice over Desk Phone Provisioning I'm here, ready to be your partner in enhancing your communication systems. Reach out to me here on Upwork and let's start a conversation, looking forward to understanding your unique needs and finding the perfect solution for you!

I build production-grade AI voice agents, RAG pipelines, and LLM-powered SaaS platforms using Vapi, Retell AI, Twilio, Deepgram, and ElevenLabs. 12+ years as a full stack developer and founder of Tech Stone Global, serving clients across North America. Most AI developers can build a demo. I ship systems that survive real users, real call volume, real revenue, and strict SLA requirements. 🎙️ 𝐀𝐈 𝐕𝐨𝐢𝐜𝐞 𝐀𝐠𝐞𝐧𝐭𝐬 (𝐂𝐨𝐫𝐞 𝐒𝐩𝐞𝐜𝐢𝐚𝐥𝐭𝐲) End-to-end AI voice agents and AI receptionists: inbound and outbound calling, appointment booking, lead qualification, real-time transcription, sentiment analysis, CRM integrations (GoHighLevel, HubSpot, custom), and human handoff flows. ✔ Vapi, Retell AI, Bland when you need fast platform-based deployment ✔ Custom Twilio + Deepgram + ElevenLabs pipelines when you need full control over latency, cost, and conversation logic ✔ OpenAI, Claude, and open-source LLMs for the conversational layer Recent work: HopDial, a VoIP platform with call transcription, AI sentiment analysis, and scalable AWS infrastructure, plus outbound AI calling systems and AI receptionists for SMBs and service businesses. 🚀 𝐑𝐀𝐆, 𝐋𝐋𝐌 & 𝐀𝐈 𝐒𝐚𝐚𝐒 I run my own production products, so I know what breaks at scale and what actually generates revenue: ✔ Legal AI platform: production RAG system (LangChain + vector search) serving ~4,000 active users ✔ ProNotepad: Next.js SaaS with AES-256 encryption, voice-to-text, and AI features. 1,000+ users on web and Android ✔ WhoseNo: reverse phone lookup platform with 2.68M+ phone records and steady daily traffic ✔ WhatsApp-first AI business automation platform, plus AI chatbots for web and WhatsApp Client work includes real estate transaction platforms (Next.js), pharmaceutical marketplaces (React Native + NestJS), and private dining and booking platforms. 🛠️ 𝐏𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧 𝐒𝐭𝐚𝐜𝐤 Voice AI: Vapi, Retell AI, Twilio, Deepgram, ElevenLabs AI / LLM: OpenAI, Claude, LangChain, RAG (Pinecone, Chroma) Frontend: Next.js, React, React Native, Tailwind Backend: Node.js, NestJS, FastAPI, Python Databases: PostgreSQL, MySQL, MongoDB, Prisma Infrastructure: AWS (EC2, Lambda, S3), Cloudflare, Docker Rapid MVPs: Bubble combined with custom APIs and AI agents when speed-to-market matters I only list what I've shipped in production, not tools I've experimented with. 🎯 𝐖𝐡𝐨 𝐈 𝐖𝐨𝐫𝐤 𝐁𝐞𝐬𝐭 𝐖𝐢𝐭𝐡 1. Founders building serious voice AI or AI SaaS products 2. SMBs and service businesses (clinics, real estate, agencies) that want AI calling agents to book appointments and convert leads 3. Funded startups scaling from prototype to production 4. Agencies needing a senior AI and architecture partner 5. Teams on Bubble that want real AI and backend systems behind their app 12+ years means I've already made the expensive mistakes, so you don't have to. You get clean architecture, honest timelines, and production-ready systems your next developer won't struggle to maintain. If you're building something serious with AI voice agents, RAG, LLM apps, or AI SaaS, send an invite and share your idea. I'll respond with a technical breakdown, not a generic pitch. Keywords: AI Voice Agent Developer, Voice AI, AI Receptionist, AI Agent Development, AI Automation, AI Chatbot, Vapi, Retell AI, Twilio, Deepgram, ElevenLabs, RAG, LLM, LangChain, Full Stack Developer, Next.js, Node.js, FastAPI, Appointment Booking, Lead Qualification

✅ 12+ Years in Mobile Development 🏆 Top Rated | Kotlin, iOS, SDKs, BLE, VoIP & System-Level Android Apps I help businesses build stable, production-ready Android/iOS applications designed for long-term reliability, scalability, and real-world usage. Over the last 12+ years, I’ve worked on Android/iOS apps ranging from consumer products to enterprise systems, including VoIP platforms, Android SDKs, BLE integrations, location tracking systems, streaming apps, and custom Android OS-level features. My focus is building and maintaining Android/iOS systems that remain stable, maintainable, and performant over time. 🚀 What I can help you with: ✅ Native Mobile App Development (Kotlin & iOS) ✅ Android SDK Development & Integration ✅ BLE (Bluetooth Low Energy) Applications ✅ VoIP, Audio/Video Calling & Streaming Apps ✅ Background Services & Foreground Services ✅ Existing App Maintenance & Bug Fixing ✅ Play Store Release & Compliance ✅ Performance Optimization & Stability Improvements ✅ Custom Android OS / System-Level Features ✅ Long-Term Product Development & Support ⚙️ Core Android Expertise: ✔ Jetpack Compose & Modern Android Architecture ✔ MVVM, Clean Architecture & Modular Codebases ✔ Firebase, Firestore & Realtime Systems ✔ REST APIs, WebSockets & SignalR ✔ Google Maps & Real-Time Location Tracking ✔ Media Streaming & Real-Time Communication ✔ Offline Storage & Sync Solutions ✔ Push Notifications & Background Processing ✔ In-App Purchases & Subscription Systems ✔ Kiosk Mode & Device Management 🔥 Specialized Experience: ✔ Android SDK development used across multiple applications ✔ BLE communication & external device integrations ✔ WebRTC, Twilio & Linphone integrations ✔ Enterprise Android systems with long-term maintenance ✔ Performance-critical and reliability-focused Android apps 🏢 Some Projects & Domains Worked On: ✔ Spirit Airlines ✔ Santander UK ✔ Plickers ✔ Ringplan VoIP ✔ Tracking & Logistics Applications ✔ Enterprise Cargo & Retail Systems I personally oversee projects from architecture to final delivery. For larger engagements, I collaborate with my in-house team of 25+ developers across Android, iOS, Flutter, backend, QA, web, and DevOps - giving clients a single point of contact backed by complete execution support. If you're building a new Android/iOS product, scaling an existing app, or solving complex Android/iOS issues, feel free to message me. Happy to review your app or requirements before we start.

SMS Marketing & 10DLC Expert | 10+ Years | High-Volume Campaigns | Compliance | Fast Setup I help businesses set up, run, and scale SMS campaigns — and make sure they're compliant with the carrier rules that determine whether your messages actually get delivered. 10+ years in mobile messaging. Millions of messages sent monthly. End-to-end coverage from strategy and platform setup to 10DLC registration and compliance. ──────────────────────────────────────── 📋 10DLC COMPLIANCE & REGISTRATION I run an SMS marketing and communications company based in the US. 10DLC compliance, registration, and approvals aren't a side service for me — they're core to what I do. I'm not learning the rules from a blog post. I'm dealing with carrier decisions, aggregator updates, and rule changes in real time. When things shift — and they shift often — I already know about it. THE PROBLEM MOST BUSINESSES DON'T SEE COMING Getting rejected is frustrating. Not knowing why is worse. Some campaigns get approved but messages are still blocked because the setup isn't actually compliant end to end. I've gotten campaigns approved that others couldn't get through — and my reviews speak to that directly. I work fast. I know where the friction points are, how carriers and aggregators actually interpret the rules, and how to structure registrations that hold up. What I handle: ✔ 10DLC brand & campaign registration ✔ Toll-Free number verification ✔ Short code compliance ✔ Blocking & filtering — diagnosis and resolution ✔ Compliance audits for existing setups ✔ Opt-in language & compliance documentation ✔ Twilio, GoHighLevel, Telnyx, Simplewire, Plivo, and other major aggregators Note on high-risk traffic: For carrier-flagged categories like cannabis, loans, and adult content, I can provide expert guidance on the current environment and your realistic options, though I can't guarantee specific outcomes. Feel free to reach out with your situation. Please note that my posted rate is if I am providing the SMS service through my company. If you need consulting with another provider my rate is $275 an hour. I also offer 30 min consults for $175. ──────────────────────────────────────── 📱 SMS MARKETING CAMPAIGNS From a single launch campaign to an always-on high-volume program, I handle strategy, execution, and everything in between. ✔ Campaign strategy, setup & execution ✔ Platform access & managed sending ✔ Mobile number lookup & list scrubbing ✔ API & integration support including Zapier ✔ Deliverability monitoring & reporting ✔ High-volume SMS at wholesale rates FAST-TRACK SETUP AVAILABLE For compliant, non-high-risk campaigns: platform access, number provisioning, and everything needed to start sending in 48 hours. Premium service, priced accordingly — ideal for businesses that need to move fast without cutting corners on compliance. Industries served: E-commerce & Retail · Real Estate & Property Management · Media & Publishing Health & Wellness · Financial Services · Personal Services · Home Services Education & Training · Restaurants & Events · Music, Film & TV · Auto ──────────────────────────────────────── Feel free to reach out with questions or to discuss your project. Happy to talk through what you're building and whether I'm the right fit. Looking forward to working with you! Thanks, Steve