When the volume is low, it amplifies the volume when you want to listen at a higher volume than the maximum volume.

How to use: Click the button at the top, set the screen overlay permission, and set the button size to be larger than 0, then the volume button will appear. You can change the position or rotate the volume button in the advanced features.

Reason for using foreground service permission: When the volume button is shown on the screen, the foreground service is used and the service is stopped when the button is turned off.