When using the accelerometer as a joystick to automatically control MMF movements, the centre position is when the iOS device is flat, facing upwards. This is ok for marble maze games but not ideal for other types of games where you would want to hold the iOS device at an angle.

Could a calibration action be added to set the centre of the accelerometer to the current angle, so you can tilt it up and down from that position. The calibration needs to register only on the Y axis for the current orientation (portrait or landscape).