Glad you like it! It's currently serving my music playing purposes quite well.

I've got a few ideas floating in my head about this kind of thing.

I did not know that its part of the .ogg spec to have gain tags, I thought I could make an external service that would parse the music file and decide what volume it should be played at, and store the info in a tracker tag. In the past I have run my collection through a normalisation program like mp3gain.

If the tags already exist, they might be picked up by Tracker already, which makes things easier

Not sure when I will be able to get around to implementing some of this stuff, hoping to get a new version out soon with MPRIS DBus support and a few other fixes.

EDIT: there looks like a number of different library parsers and players that support the tag method so this is definitely something to add to the TODO list, thanks