Xiang Z.

𝐀𝐥𝐥 𝟓-𝐒𝐭𝐚𝐫 𝐑𝐞𝐯𝐢𝐞𝐰𝐬.🌟 𝐓𝐨𝐩 𝐑𝐚𝐭𝐞𝐝 🌟 • 𝐓𝐨𝐩 𝟏𝟎% 𝐨𝐟 𝐔𝐩𝐰𝐨𝐫𝐤 𝐅𝐫𝐞𝐞𝐥𝐚𝐧𝐜𝐞𝐫𝐬 🥇 A Senior Fullstack & Mobile Developer with over 12 years of experience delivering high-quality software solutions for web and mobile applications. I have successfully built and launched 30+ mobile apps, many of which are live in the App Store and Google Play. I do not just write code — I help clients move their product from idea, MVP, or existing web app to a real mobile app that can be tested, submitted, and launched. I help founders, startups, and businesses build, fix, and launch production-ready mobile apps for the App Store and Google Play. With 12+ years of software development experience and 30+ launched mobile apps, I specialize in iOS, Android, cross-platform mobile development, backend integration, in-app purchases, authentication, AI-powered features, and app store release support. My strongest areas include: ✅ iOS development with Swift, SwiftUI, UIKit, and Objective-C ✅ Android and cross-platform apps with Flutter, React Native, Expo, and Capacitor ✅ App Store and Google Play submission, TestFlight, internal testing, closed testing, and review issue fixes ✅ In-App Purchases, subscriptions, RevenueCat, Superwall, Stripe, and payment flows ✅ Supabase, Firebase, Firestore, PostgreSQL, MySQL, MongoDB, and backend integrations ✅ Apple Sign-In, Google Sign-In, Firebase Auth, Supabase Auth, and social login flows ✅ AI app development using OpenAI API, Claude, DeepSeek, and other AI integrations ✅ Push notifications, APNS, FCM, maps, background location, Bluetooth, and real-time features ✅ Existing app maintenance, performance improvement, bug fixing, and production issue resolution I can help you with: - Turning web apps, Lovable, Bolt, Replit, FlutterFlow, Base44, or existing MVPs into iOS and Android apps - Building complete iOS and Android apps from scratch based on designs created in Figma, Adobe XD, or Sketch - Turning UI/UX designs into pixel-perfect, responsive mobile applications - Developing complete backend systems, databases, APIs, authentication, and admin dashboards - Handling the complete development lifecycle—from UI implementation and backend development to testing and App Store/Google Play release - Preparing iOS and Android builds for TestFlight and Google Play testing - Fixing App Store and Google Play rejection issues - Setting up subscriptions, paywalls, free trials, and restore-purchase flows - Integrating Supabase, Firebase, RevenueCat, Stripe, OpenAI, and other third-party services - Building AI-powered mobile features such as chat, analysis, content generation, voice interaction, and automation - Improving existing apps, fixing production issues, and preparing them for release Tech stacks I work with: Mobile: Swift, SwiftUI, UIKit, Objective-C, Flutter, Dart, React Native, Expo, Capacitor, Android Backend: Java, Spring Boot, Go, Gin, Python, REST APIs, WebSocket, microservices Database & Cloud: Supabase, Firebase, Firestore, PostgreSQL, MySQL, MongoDB, SQLite, Redis, Google Cloud, AWS Payments & Subscriptions: RevenueCat, Superwall, Stripe, Apple IAP, Google Play Billing AI & Automation: OpenAI API, Claude, DeepSeek, AI-assisted app features, AI workflow integration I focus on clean implementation, reliable communication, and practical solutions that help your product move forward. Whether you need to launch a new app, fix an existing one, add subscriptions, solve login issues, or pass app review, I can help you get it done properly. If you need a developer who understands both mobile development and the full release process, I’d be happy to help.