Protractor and Angle Gauge is a free Android app developed by Toolkit in the Utilities & Tools category. This app allows you to measure any angle or slope with ease. It has a built-in gyroscope that lets you measure the angle between any line and a vertical. You can also measure an angle based on the photo you took and the nodes you selected.

With this app, you can finally learn how sloped that Leaning Tower of Pisa actually is! You can even recalibrate your device and use some line as a base level for your measurements. Overall, Protractor and Angle Gauge is a great app that is easy to use and provides accurate measurements.