With the Satechi Bluetooth Trigger you can control your camera’s shutter using your iPhone. That’s pretty awesome. The receiver box sits in your camera’s hotshoe mount and plugs into the controller port. The iOS app has 3 shooting modes to control your camera. Mode 1 is normal shutter release. Mode 2 is manual shot with a timer. Mode 3 is timed shot. With the Bluetooth 4.0 technology built in, you can control your camera up to 50 feet away. Perfect for those selfies!