1. A computer-implemented method comprising: receiving a first gesture or a gesture portion, at least a portion of the first gesture or gesture portion being over a first user interface associated with a first application; analyzing the first gesture or gesture portion to determine whether to pass the first gesture or gesture portion to the first application, whether to display an application-selection user interface associated with a system-interface module, or whether to display a system-control user interface associated with the system-interface module, the analyzing based, at least in part, on a starting point and a second point of the first gesture or gesture portion; responsive to determining to display the application-selection user interface, presenting, via the system-interface module, the application-selection user interface on a display, the application-selection user interface having thumbnail images for applications, each of the thumbnail images a visual representation of an application interface for a respective one of the applications, at least one thumbnail image being associated with a second application having a second user interface and at least one thumbnail image being associated with a third application having a third user interface, the second application and the third application being different, the system-interface module being associated with launching applications; receiving a selection of one of the thumbnail images and through a second gesture or a later gesture portion; responsive to receiving the selection, dragging the selected thumbnail image to a region of the display based, at least in part, on the second gesture or the later gesture portion; and based on the region of the display to which the selected thumbnail image is dragged, presenting the application interface associated with the selected thumbnail image, the presenting effective to enable interaction with a selected application associated with the selected thumbnail image.