Too difficult to access the             USB port on your compact             2-4" quad? Say goodbye                                    It's time to say goodbye to this trouble With this Bluetooth             stack, you don't need to connect your quad to the PC for             FC and even ESC tuning, everything can be done             wirelessly in the SpeedyBee app.                                                                                                           Tune Flight controller             and ESC wirelessly                                    Power the quad, connect the SpeedyBee app via             Bluetooth, configure the UART Ports,PID,OSD and             every other settings on this flight controller Also,             every parameter of the BLHeli_S ESC in this             stack can be set via the app.                                                                                                           Change motor directions             wirelessly                                    With this stack, when you finish your build, connect to the             SpeedyBee app, change the motor directions just in             a few simple steps. Then take off.