A Fitbit app.
Fitbit device side,
1. Fitbit Ionic (target, SDK v4.2)(cross support to SDK v5)
2. retrieve various sensors readout
3. sending sensor data on an event and periodic schedule
4. push sensor data to backend using MQTT
1. retrieve from backend
2. stream audio file to a headset via Bluetooth profile or BLE.
Developer to provide working project source.