As you listen to music on your iOS device, you can move forward and back between tracks with the designated buttons in the Now Playing widget. But if your handset is in your pocket, then you can’t switch between tracks without first pulling the device out of your pocket.
JumpSkip is a new free jailbreak tweak by iOS developer Karimo299 that lets you move forward and back between music tracks without taking your device out of your pocket; instead, you can articulate specific volume button sequences to accomplish this task.