A free app for Android, by Kazeka SDL.

360 Degree Protractor, Level, Goniometer is a one-stop solution for your angle measurement needs. With this handy and compact app, you can have your protractor, level, and goniometer all in one place. You will never have to bring the actual tools with you. Bring these measuring tools in your pocket and use them whenever and wherever you need them. 

Thanks to this app, you will be able to measure angles at hand with a few clicks. Choose which tool to use and it will provide the measurement in degrees within a few seconds. Plus, it features a well-designed user interface that will let you handle measurements in a convenient way.