Car Compass Overlay

Compass works on the devices with compass/magnetic field sensors and without such. It can use "GPS Mode" to determine the moving car direction. In "Compass Mode" the shown azimuth is between North and the device pointing direction. Device can be used in both flat and upright position, both horizontal and vertical orientation. In "GPS Mode" it requires your device to be moving. Shown azimuth then is between North and the direction of your movement.