Currently, the Android client code has a feature to fail the firmware flash quickly when the USB Manager can't find a Crazyradio PA( in the BootloaderActivity). As the Android client connects to the Crazyflie directly over BLE as well, introducing a firmware flashing feature over BLE can be a good upgrade.
This is implemented in the iOS client. As far as I understand, the only thing missing to the android client to implement bluetooth bootloader is a working bidirectional BLE link?
Currently, the Android client code has a feature to fail the firmware flash quickly when the USB Manager can't find a Crazyradio PA( in the BootloaderActivity). As the Android client connects to the Crazyflie directly over BLE as well, introducing a firmware flashing feature over BLE can be a good upgrade.