The flash module on most smartphones isn’t just useful for taking pictures in low-light conditions. It can also serve as a flashlight. This comes in handy in many different situations, like, for instance, when you’re having a hard time unlocking your front door late at night.

A flashlight is a portable hand-held electric light. The source of the light is usually an incandescent light bulb or light-emitting diode. A typical flashlight consists of the light source mounted in a reflector, a transparent cover to protect the light source and reflector, a battery, and a switch.