A method, comprising: at an electronic device with a touch-sensitive display: while displaying a user interface that includes a first region that corresponds to a first software application and a second region that corresponds to a second software application that is distinct from the first software application: receiving a first touch input, on the touch-sensitive display, that originates from a first location on the touch-sensitive display that corresponds to the first region of the user interface and extends to a second location on the touch-sensitive display that corresponds to the second region of the user interface; and, in response to receiving the first touch input: in accordance with a determination that the first location corresponds to a non-boundary region of the first region, processing the first touch input with the first software application, wherein the non-boundary region of the first region is included in the first region and located away from the second region in the user interface; and, in accordance with a determination that the first location corresponds to a boundary region of the first region and that the first touch input has not entered the non-boundary region of the first region on the touch-sensitive display, processing (808, 810) the first touch input with the second software application, wherein the boundary region of the first region is included in the first region and located between the non-boundary region of the first region and the second region in the user interface. receiving a first touch input, on the touch-sensitive display, that originates from a first location on the touch-sensitive display that corresponds to the first region of the user interface and extends to a second location on the touch-sensitive display that corresponds to the second region of the user interface; and, in response to receiving the first touch input: in accordance with a determination that the first location corresponds to a non-boundary region of the first region, processing the first touch input with the first software application, wherein the non-boundary region of the first region is included in the first region and located away from the second region in the user interface; and, in accordance with a determination that the first location corresponds to a boundary region of the first region and that the first touch input has not entered the non-boundary region of the first region on the touch-sensitive display, processing (808, 810) the first touch input with the second software application, wherein the boundary region of the first region is included in the first region and located between the non-boundary region of the first region and the second region in the user interface. in accordance with a determination that the first location corresponds to a non-boundary region of the first region, processing the first touch input with the first software application, wherein the non-boundary region of the first region is included in the first region and located away from the second region in the user interface; and, in accordance with a determination that the first location corresponds to a boundary region of the first region and that the first touch input has not entered the non-boundary region of the first region on the touch-sensitive display, processing (808, 810) the first touch input with the second software application, wherein the boundary region of the first region is included in the first region and located between the non-boundary region of the first region and the second region in the user interface.