AudioAngle

This app can be used to measure angles. The measured angle will be shown on the display, but also played as audio.
It is useful for e.g. ski touring to estimate the angle of a slope. (Place the ski pole on the slope and place the smartphone with the running app on the ski pole.)

Configuration:
You can select the language in the upper right corner and toggle audio output on or off with the speaker symbol.

Angle Measurement:
The measured angle is between one of the long edges of the device (at least for most devices) and the horizontal plane.
The measured angle is always between 0 and 90 degrees. Once 90 degrees is reached, the other long edge will be taken as the reference.

Liability:
The app is provided "as is" without any warranty of any kind, express or implied. The author shall not be liable for any damages arising from the use of the app.
The angle measured by this app shall not be taken as a reliable measurement for any purpose, especially not for evaluating critical situations and conditions.