KK2 is modified -by firmware only- to accept connection with XBEE which is a famous transceiver used for wireless communication.
The quadcopter sends Gyro, ACC & Motor values so that you can study actual values and enhance your stability algorithms... This feature is very useful for Quadcopter Firmware Developer.

What you can see is the monitor screen, where there are two programs running..one of them is a stream from an IP cam that shoot my quadcopter and the other is the Application "HefnyCopter Monitor App" that communicates wirlessly with quad to receive data. I fly the quad using my normal TX. The main purpose of this is to study sensors actual values and enhance stability algorithms.