1. A method, comprising: at a device with a touch-sensitive display: displaying a first unlock image on the touch-sensitive display while the device is in a first user-interface lock state, wherein the first unlock image corresponds to a first application on the device; detecting a gesture on the touch-sensitive display with the first unlock image, the gesture moving the first unlock image from a first location to a second location by continuous contact with the touch-sensitive display; determining that the detected gesture with the first unlock image satisfies a predefined condition; and transitioning the device to a user-interface active state that displays user-interface objects for the first application in response to the detected gesture satisfying the predefined condition.