Sensor Accelerometer

This app provide your device position with respect to earth.In which direction your phone is located in terms of X Y Z co-ordinates.Its sensitivity is very high which can be used in measuring even very minute acceleration of your device.
Right side of your device is +X, top side is +Y & screen side is +Z direction.
It is helpful in various ways like knowing your 3-D positioning similar to compass, you can know how fast your mobile is moving and to calculate angle of tilt of your device from any plane.
for e.g if your Y coordinate value is 5 then tilt is cos(5/9.8).This is how you come to know about tilt of your screen and more tilt means more acceleration hence more force is acting on your screen.