I'm talking about Tasker.
Basically what it does is making up for lack of functionality in your apps/phone.
I guess it's an app complimenting your apps.
At least that's what I use it for mostly.
Ever since I had the yellow waterproof sony walkman cassette player I've had this problem of gradually increasing the volume while listening to music until I turned it off. Then next time I picked it up I blew my ears out when I started playback again. All the years through discmans, minidiscs, ipods, mp3-players and music-phones I've done this so many times it's not even funny.
But I finally got an end to it. Now when I plug in my headphones the media volume is automatically turned down. I fucking love it!
There you have it. You just make it do tasks based on various contexts.
Some other examples of what I've made it do is making a sound when the battery is fully charged.
I was also getting a little annoyed of the screen timeout when I was reading RSS or playing chess, so I've added some time to the screen timeout when I'm in apps like NewsRob/ChessCom/WordFeud.
When I'm at the gym it automatically turn to vibrate mode. I've forgot to do that a couple of times and gotten a phone call in the middle of a set, sucks to cancel the set just to take that phone call. Also sucks to just let it ring having everyone around giving you this mad look, lol.
Stuff like that. Really convenient.
It's not free though, but I highly recommend it!
You don't need an app - you need to stop turning your ipod up as you listen.
I rarely listen to mine more than a third up, sometimes less.