Whenever you start or continue a flight, the accelerometer is calibrated. Before starting or continuing a flight, hold your device level in front of you, then press the start- or continue flight button and don't move your device for about one second.
Note that if you hold your device too horizontally, the accelerometer won't work correctly. If during the game you're uncomfortable with your device's position, tap anywhere on the screen to pause the game, move your device to the desired position, and continue flying.
If the virtual cockpit is enabled, you can use simple multitouch gestures to control the viewing angle, position and zoom:
Similarly, use double taps to reset angle (one finger), zoom (two fingers) or position (three fingers) respectively.
You control the orbiter's pitch axis by tilting your device. Pull the top edge of your device towards you to pull the orbiter's nose up. Push the top edge of your device away from you to push the orbiter's nose down.
You control the orbiter's roll axis by rotating your device. Rotate it to the left to roll the orbiter to the left, rotate it to the right to roll the orbiter to the right.
Don't tilt or rotate your device by more that 45° in any direction. 45° will already move the orbiter's elevons (the large control surfaces on the back of the wings serve as both, ailerons and elevators) to their maximum deflection angles. The elevons are controlled by hydraulic actuators and are rate limited, so it will take them some time to move from one extreme to the other. Be careful not to countersteer too quickly, as this could easily lead to so called pilot induced oscillation and you might lose control over the vehicle.
During the game, when you rotate the device, the display is rotated in the opposite direction. It's like viewing the head up display "through" your device.
If you don't like that, you can easily turn it off:
Tap anywhere on the screen to pause the game and press the Options button. Under Pilot's point of view turn off the Tilt with device switch. Tap Back and Continue flight to proceed.
After main gear touchdown, two red sliders appear on the bottom of the screen. These are the pedals and control the wheelbrakes and the nosewheel. Use them to keep the orbiter on the centerline and (after nose wheel touchdown) to decelerate.
Rudder, speedbrake, gear and chute are per default controlled by the autopilot. To override this setting, pause the game and navigate to the Settings → Autopilot menu. Here you can disable the autopilot (and enable manual control) for gear and cute, speedbrake, pitch correction and rudder.
Pitch correction automatically compensates for pitching moments generated by moving the speedbrake - it's highly recommended to leave this switch on. With speedbrake, rudder, gear and chute channels on manual the screen looks like this:
During flight, the rudder pedals are gray and control the rudder. After main gear touchdown, they change red and control wheelbrakes and nosewheel.