1. A device comprising: a touch screen display for displaying a screen of an application executed in the foreground; and a controller for causing, when a first gesture is performed on the touch screen display while a first application is executed in the foreground and a second application is executed in the background, the first application to perform an operation according to the first gesture, wherein the controller executes, when a second gesture is performed on the touch screen display while the first application is executed in the foreground and the second application is executed in the background, the second application in the foreground.