ime a newbie here so information from me is limited,, I definitely know it works with mine and any pixhawk flight controller..
ime pretty sure it would work as it is only sending and receiving basic signals like a normal transmitter..(although I send telemetry as well giving me satellite information,volts,amps,cell information)
the app I use is tower app for android phone.. I can fly guided mode where u set height and then you just point to map on screen,, and then the quad flies there (flight controller uses gps for this mode)
other modes (manual control with self levelling enabled will give you control to fly using phone screen as a transmitter) NO GPS
follow me mode,, I can set the height and distance, and my quad will follow me/my mobile phone.. (I tested this when on my trials bike - the quad kept up to me at 40+mph)
Laptop ---- I use mission planner to control quadcopter - (can also connect joystick to control quadcopter plus send av signal from quadcopter to laptop and overlay onto flight screen HUD)
htc android phone --- I use tower app
DEFFO check out droneshop.biz ... bottom of the page is a link to videos -- I rang the owner direct and he has helped me on the phone with a few problems.. a very nice man.. (Peter King)
ill try find out more about the kk2 board in the meantime -- my knowledge on flight controllers is limited, but growing fast,, i love this hobby..