Spirit Level is an Android app developed by keuwlsoft that transforms your device into a bubble level. It is a free utility tool that is compatible with Android 9.0. The app requires calibration for accurate readings, which can be done by touching the CAL button. The app features a bulls-eye level with roll and pitch gauges screen, as well as horizontal and vertical bubble level and angle gauge screens.

The app includes a pause button to hold the current reading and a zero and reset button to make measuring angles easier. Additionally, there is an option to auto-select the screen based on inclination. However, it is essential to note that the accuracy of the app depends on the device's accelerometer. Therefore, it should be used for indication purposes only. For accurate readings, it is best to use a real spirit level. Overall, Spirit Level is an excellent app for those who need a quick and easy way to measure angles on the go.