Bubble Level is a free application for Android phones. The application creates an image of a spirit level bubble vial on the screen of the phone. Bubble Level works in all three orientations: flat phone (surface level), horizontal phone and vertical phone. A calibration feature is included in the menu options. Accuracy is displayed to tenths, and can be read in various modes: degrees, percent, inches/foot (fractional & decimal), and mm/m. Additional features include Hold and Sound. Use it to straighten shelves, adjust hanging pictures, or cheat on your golf putts. Bubble Level works with all phones or tablets running the Google Android operating system.