The Crazyflie iPhone client supports only Crazyflie 2.X with Bluetooth LE communication. It is compatible with iPhone 4s+ and iOS 7.1+.
User documentation
The main screen allows to connect the Crazyflie 2.X by clicking connect. When connected the button is changed to “disconnect” and the top progress bar is filled up.
To start flying place both thumb on both side of the screen. Two blue square appears, they represent two touch joystick.
The control sensitivity and joystick mapping (control mode) is available clicking the settings button:
