Valery B.

I build mobile apps from scratch, from UI/UX design to App Store and Google Play launch, and fix, rebuild and scale existing apps. Did you know 71% of users uninstall an app after a single crash or major UI lag? I don't build disposable apps, I engineer high-retention mobile products. Last year, my React Native architecture helped a FinTech client scale to 50,000+ daily active users while maintaining a 99.9% crash-free rate and cutting cross-platform maintenance costs by 40%. You need a secure, lightning-fast app that keeps users hooked? Let's build it right the first time. I take mobile products from idea to store launch and support: UI/UX design, development, backend, API integration, testing and release, as one developer who owns the entire mobile product (full stack: React, Node.js, cloud). WHAT I DO 📱 Mobile app development from scratch: React Native, Flutter, iOS & Android Cross-platform and hybrid apps for smartphones and tablets (iPhone, iPad, Android): React Native with Expo and Firebase, Flutter and FlutterFlow, TypeScript, clean architecture that stays easy to maintain. MVP apps for startups and full production apps. 🎨 Mobile app design: UI/UX in Figma Wireframes, mockups, prototypes and design systems for iOS and Android, mobile UI kits ready for developer handoff, redesign of existing apps, user flows and onboarding that convert. Design and development under one roof, so nothing gets lost between the two. 🍎 Native iOS & Android development iOS apps in Swift, Android apps in Kotlin and Android Studio, native modules and bridges for React Native and Flutter (encryption, Bluetooth, GPS, biometrics). 🔌 Backend, API integration & real-time features Node.js, Express.js, REST API and GraphQL, Firebase, Supabase, PostgreSQL, MongoDB. User authentication and profiles, biometric login, push notifications, real-time chat and messaging, video streaming, maps and GPS tracking, Bluetooth sensors, offline mode. 💳 Payments & in-app purchases In-app purchases and subscriptions, Stripe and PayPal checkout, secure payment flows for e-commerce, marketplace and fintech apps. 🤖 AI mobile apps AI app development: AI voice chatbots, smart assistants and personalization inside React Native and Flutter apps, AI model and API integration. 🔧 Rebuild, bug fixing & performance Taking over and rebuilding existing iOS and Android apps, migrating to React Native or Flutter, crash fixing, performance tuning (faster launch and load times), release automation, ongoing support and feature development. 🚀 App Store & Google Play launch Store listings, TestFlight and closed testing, submission and review fixes, updates after launch. 📊 INDUSTRIES Healthcare · Fitness · FinTech · E-Commerce · Education · SaaS · Dating Apps · Real Estate · Travel · Marketplaces · Gaming · MVP Startups 💡 PROJECTS I'M PROUD OF 🔹 FinTech mobile app (React Native): cross-platform personal finance app with 10,000+ active users and $1M+ in annual transactions; user profiles, authentication and biometric login via API integration; engagement up 40% through design and performance work. 🔹 Educational mobile app (Flutter): video streaming and quizzes used by 15,000+ students worldwide; load times cut by 50%; gamification and in-app messaging. 🔹 E-commerce mobile app (React Native + GraphQL): offline mode, fast checkout and push notifications, 27% higher mobile conversions; secure payments, iOS and Android delivery end to end. 🤝 WHY WORK WITH ME ✅ 10+ years in mobile app development across iOS, Android, Flutter and React Native ✅ Design + development + backend in one person: fast, stable, conversion-optimized apps ✅ Full stack: React, Node.js, API integration, cloud infrastructure ✅ MVP to scale: from idea through store launch and long-term support 📱 TECH STACK Mobile: React Native, Expo, React Native Firebase, Flutter, FlutterFlow, Swift, Kotlin, Android Studio, Bubble Frontend & design: React, JavaScript, TypeScript, Tailwind CSS, CSS3, HTML, Material UI, Figma Backend & API: Node.js, Express.js, GraphQL, REST API, user authentication, push notifications Database & cloud: MongoDB, PostgreSQL, Firebase, Supabase, AWS, Docker 📩 Ready to build your mobile product? Invite me to your job or send a message with your idea or a link to your app, and I will reply with a first plan. 📆 Last Updated: 11/3/26