Crypto Exchange Mobile App

I already run a live crypto-exchange and all core services are exposed through a documented REST/WebSocket API. What I now need is a polished native (or cross-platform) mobile application that talks directly to those existing endpoints, giving my users a fast, secure and intuitive on-the-go trading experience.

Here’s the scope as I see it:

• Interface & UX
Design and build a modern, brand-consistent interface that feels at home on both iOS and Android. I will supply logos, colour palette and wireframes for the key screens; you’re free to refine the micro-interactions and visual polish.

• API Integration
Hook every screen into the current API layer—account creation/login, balance retrieval, order book streaming, trade execution, deposits/withdrawals, and basic settings. I’ll provide a Postman collection, test keys and a staging server for verification.

• Security & Auth
Implement a secure authentication flow using my existing token system; the app must store nothing sensitive in plain text. Two-factor and biometric unlock are already supported by the API and should be surfaced to the user.

• Notifications
Push or in-app notifications for order fills, price alerts and system messages.

• Testing & Delivery
Send regular TestFlight / Google Play Console builds, fix bugs quickly and hand over all source code, build scripts and lightweight documentation so my internal team can maintain future versions.

I want clean, well-commented code, adherence to best practices (Swift/Kotlin or React Native/Flutter—open to your recommendation) and a timeline we can both commit to. If you have genuine crypto or fintech app experience, do highlight it when you respond.