I am beginning tests on the PhoneDrone (still waiting to receive my DroneCell, so I'll go with what I have here).
I've connected the PhoneDrone to the APM1's Telemetry port on the top of the IMU. With a simple arduino sketch, I can read the data from the APM, forward it to the other serial port and over USB to Mission Planner or Qgroundcontrol.
So basically:
APM --> PhoneDrone --> USB…