Volta appVolta is System tool that is open source under the GPL-3.0-only license. Tiny app to add several actions to volume buttons.
* Long Volume Up - next track
* Long Volume Down - previous track
* Double Volume Up - flashlight/broadcast
* Double Volume Down - flashlight/broadcast
Does NOT work when the screen is fully off. For a better user experience use Key Mapper.
* ACCESSIBILITY - receive volume key events
* VIBRATE - notify on action success
* FLASHLIGHT - toggle flashlight
It is Free Open Source Software.