An electronic device displays an application switching user interface. The device, while displaying the application switching user interface, detects a touch gesture by a contact. In response to the touch gesture: if the touch gesture includes movement by the contact in a first direction and started at a location that corresponds to an application representation corresponding to a respective application, the device closes the respective application; and, if the touch gesture includes movement by the contact in the first direction and started at a location that corresponds a predefined region in the application switching user interface that is outside of the representations of respective applications, the device ceases to display the application switching user interface and displays an application launching user interface.