After charging the controller due to the experimenting I've done, I've found that once the controller boots up, plug a loose end of the USB into the corresponding jack. The popup will ask you which app you want to use. Since I'm not sure which, and don't want to set a default as of yet, I choose Litchi, then tap Just Once. Start the aircraft and once Litchi has loaded, the aircraft should connect to the R/C. The USB cord needs to stay plugged in. When you unplug one end or the other you'll lose connection with the aircraft.