Bluetooth Data Transfer App

I need a compact, reliable Bluetooth application focused purely on data transfer between a smartphone and an external device. Pairing is only a means to that end; the app’s main task is to connect quickly over BLE and move data packets back and forth with minimal latency and zero drops... (Budget: $750 - $1500 USD, Jobs: Bluetooth, Flutter, iPhone, Kotlin, Mobile App Development, Objective C, React Native, Swift)