RainbowTunes allows you to create tracklists of favourite music using rainbow colors. Just draw your rainbow by long touching on map and select tracks in every circle of rainbow. Your current location is the center of the rainbow. The app checks your current location and plays the list of tracks which you've chosen for the current circle. All the tracklists are played independently. The app also works in background mode.
Continued use of GPS running in the background can dramatically decrease battery life.