A method of operating a mobile computing device , the method comprising: concurrently running, on the mobile computing device , multiple applications each representable on a display screen of the mobile computing device by a corresponding card containing a user interface for the corresponding application; placing a first application of the multiple applications into a hibernation state, wherein the corresponding card of the first application comprises a static snapshot of the user interface for the first application; toggling, in response to a user input, operation of the mobile computing device from a full-screen mode to a card mode, wherein while operating in the card mode, the method further comprises: displaying, on the display screen , the cards in a linear arrangement along an axis of the display screen ; moving, in response to a directional touch input provided by a user along the axis of the display screen , the cards across the display screen in the same direction as the directional touch input; and detecting the user tapping the corresponding card of the first application displayed on the display screen ; toggling, in response to the user tapping the corresponding card of the first application, operation of the mobile computing device from the card mode to the full-screen mode; and reviving the first application in response to the user tapping the corresponding card of the first application, irrespective of a position of the corresponding card displayed on the display screen . concurrently running, on the mobile computing device , multiple applications each representable on a display screen of the mobile computing device by a corresponding card containing a user interface for the corresponding application; placing a first application of the multiple applications into a hibernation state, wherein the corresponding card of the first application comprises a static snapshot of the user interface for the first application; toggling, in response to a user input, operation of the mobile computing device from a full-screen mode to a card mode, wherein while operating in the card mode, the method further comprises: displaying, on the display screen , the cards in a linear arrangement along an axis of the display screen ; moving, in response to a directional touch input provided by a user along the axis of the display screen , the cards across the display screen in the same direction as the directional touch input; and detecting the user tapping the corresponding card of the first application displayed on the display screen ; toggling, in response to the user tapping the corresponding card of the first application, operation of the mobile computing device from the card mode to the full-screen mode; and reviving the first application in response to the user tapping the corresponding card of the first application, irrespective of a position of the corresponding card displayed on the display screen . displaying, on the display screen , the cards in a linear arrangement along an axis of the display screen ; moving, in response to a directional touch input provided by a user along the axis of the display screen , the cards across the display screen in the same direction as the directional touch input; and detecting the user tapping the corresponding card of the first application displayed on the display screen ; toggling, in response to the user tapping the corresponding card of the first application, operation of the mobile computing device from the card mode to the full-screen mode; and reviving the first application in response to the user tapping the corresponding card of the first application, irrespective of a position of the corresponding card displayed on the display screen . <EOS>