iOS & Android Trading App

I need an experienced mobile developer to create a real, reactive trading application that runs on Both iOS and Android. After secure User authentication, the flow should let customers add orders to a Shopping cart–style queue, then complete the purchase through an in-app Payment gateway. Although the focus is trading, I still want the cart paradigm so users can review positions before committing. Real-time prices, order history, notifications, and basic account management will finish the first release. Clean, maintainable code and a native-feeling interface are essential. I am open to Swift/Kotlin, React Native, Flutter, or another modern stack—just explain why your choice best suits low-latency trading. Deliverables • Fully functioning iOS and Android builds uploaded to TestFlight and Google Play Console (internal track) • Complete, well-commented source code with build instructions • API integration hooks documented (backend endpoints provided by me) • Short hand-over session to walk through the build and deployment process When you reply, please outline your proposed tech stack, estimated timeline, and links to any trading or e-commerce apps you have shipped.