The app is 3 apps in 1: it is a compass, it is a pointer to a location and it is a satellite finder or pointer. This app is ads free and is completely free.

As a compass it displays the current location and the magnetic declination of the location. With the help of a real compass you can verify that the phone's compass is pointing correctly to North-South.
The app needs to know the location which is found via GPS or entered via manual input (typed in) ad numbers in degrees or as an address.