If you can't see the compass icon in the upper left corner of the Star Walk 2 main screen, it means that your device is not equipped with digital compass(magnetometer) that is required for the Star Spotter (the feature that allows you to track the sky) to be activated. Otherwise the app works as advertised on your device. You can use Star Walk and track the sky and observe stars, satellites, constellations in their proper place for your current location.