Donwload here [play market] construction-level.
This app shows angles of inclination of the device to the ground.
The app uses an accelerometer, so you should have it on your device.
Install the following software:
Run debug build
./gradlew :app:clean :app:assembleDebug
Run unit tests
./gradlew testDebug
[More info] android test info
Install on device
./gradlew :app:installDebug