Use the app to find out the altitude (inclination in degrees, NOT height) and azimuth of any point you wish.
The app shows you a 3d representation of the direction (bearing) . It acts as a compass and shows you North, South, East and West along with other intermediate directions. The altitude of the object being pointed is shown and can be used as a sextant. Long press to take a snapshot of the Altitude and Azizmuth readings.
The orientation of the phone in terms of pitch, yaw, and roll is given along the magnetic strength reading.
The altitude and azimuth is a local coordinate system used to locate objects like stars, planets and other heavenly bodies on the celestial sphere, it is very useful in Astronomy.

You can change the mode of movement of the compass by toggling the "Fixed" entry in the menu.