An electronic device having a touch-screen display detects a first input on the display while displaying a first user interface on the display. In response to detecting the first input on the display, the device enters a flashlight mode. Entering the flashlight mode includes replacing the first user interface with a first flashlight user interface. The first flashlight user interface has a first total lumen output and a first luminance that is substantially uniform over the display. The device determines whether brightness change criteria are met, and in accordance with a determination that the brightness change criteria are met, displays a second flashlight user interface having a second total lumen output greater than the first total lumen output and a second luminance that is substantially uniform over the display.