You need to start the tool manually or add a shortcut in the startup folder.
Features:
open using volume hardware buttons if running in background
to change volume use the + / - buttons or swipe with your finger
use scroll wheel to change volume
switch between phone and ringer volume
basic skinning support
customizable settings - see settings.ini
VGA support
commandline parameters -hide / -inc / -dec
Todo:
open when clicking the volume icon
transparent background