Crypto Exchange Mobile App Development

I already run a fully documented exchange API and now need a high-performance mobile front end that brings the entire trading experience to people’s pockets. The app has to ship simultaneously on iOS and Android, sharing as much code as practical while still feeling native on each platform... (Budget: $5000 - $10000 USD, Jobs: Android, Android App Development, API Development, Cryptocurrency, iOS Development, iPhone, Mobile App Development, React Native, Security, Software Architecture)