Inclinometer is a free Android application developed by Stephen Tenniswood. It is a simple yet useful tool that determines the angle of incline from horizontal. The app is helpful when you need to measure the slope of a surface with gravity or level a picture. It offers a beep option that becomes faster the farther you are from horizontal.

The app's user interface is straightforward, and it's easy to use. You can adjust the beep frequency, sensitivity, and orientation mode. In addition, the app is lightweight and doesn't take much space on your device. However, if you need more features, you can get the pro version of the app, which offers pitch/roll info, quick calculations, measurements, grade, and graphics.

Overall, Inclinometer is an excellent tool for anyone who needs to measure slopes and angles. It's simple, accurate, and free. The app is perfect for DIY enthusiasts, architects, engineers, and anyone who needs to measure angles.