This is a recommended app for you who go to the mountains.
It will be a notification of whereabouts by bear bell and light.

For example, you can use it like this. Please try.
1.Launch the app and start bell sound.
2.Press the power button and put it in your pocket. Even in this state, bell sound will continue to ring at the set interval and volume.
3. If you suddenly feel uneasy (you can leave the power off), quickly shake your phone from side to side.
4. The light turns on at the same time as the emergency sound (thunder) sounds.
5. An emergency sound and lighting of the light can inform a person a little far away of your whereabouts.

◇Volume
Select from 1 to 15
(1: terminal minimum, 15: terminal maximum)

◇Continuous playback interval
Select from 0, 1, 3, 5, 7, 10, 15, 20, and 30 seconds
(0: Continuous playback without delay)

◇Sound type
bell, thunder, firecracker, firework, radio, whistle
Select playback sound from 3 types

If trouble occurs using this application, please solve it yourself. "TF's apps" is not responsible at all.