Handling input devices is essential to any application, but probing sensors is important for the smartest one! The most spread sensor among Android game applications is the accelerometer.
An accelerometer, as its name suggests, measures the linear acceleration applied to a device. When moving a device up, down, left, or right, the accelerometer gets excited and indicates an acceleration vector in 3D space. Vector is expressed relative to screen default orientation. Coordinates system is relative to device natural orientation:
Axes become inverted if device is rotated (for example, Y points left if the device is rotated 90 degrees clockwise).
A very interesting feature ...