The compass is the instrument cluster for getting directions.
Compass app will determine the direction of the magnetic field.
The earluff displays the azimuth at the top of the screen.
This compass app displays the GPS altitude.
This app shares your location with others, and shows the location on a map.
This compass app helps you display the correct bearing by displaying the tilt of the compass.

Make sure that third-party apps are allowed on your device: go to Menu->Settings->Security-> and check "Unknown Sources"

Tap the APK file. Allow the app any required permissions it asks for. Then, at the bottom of the installer window, click INSTALL.

You'll see a confirmation the app is installed. Now you'll see the app available in your list of installed apps.