Originally Posted by
Robert Crist My method involves holding the back key until the task switcher comes up. With the latest update you can hit the X in the top right corner to close background applications.
Tapping the X in task switcher is only available with GDR3, which has not been officially released, and this does not close applications running in the background. To do this, go to settings, swipe left to the applications screen, and then tap background tasks. All of the listed applications with "allowed" in green are running in the background. Tap each application you want to stop running.