Virtual Spirit level (bubble level) is an app that helps you to measure slopes
Virtual Bubble Level Pro ( Virtual Spirit level ) is a free android application that helps you measure any slopes on all sides using your mobile phone.
This app is designed to indicate all angles of different horizontal or vertical surfaces also can measure the angle of inclination as the inclinometer (or clinometer).
Using this application is very simple it is like any traditional bubble level.
A very big thank you for Antoine Vianey for his code, and also great thanks to Melchisédech Thévenot for his useful invention of this measuring tool (Spirit level).