September 2015
Tapping your phone's screen to take a picture sounds good in theory, but in practice it can make shots a little shaky. Here are some better options.
iPhone
Point your camera and press the phone’s Volume Up button.
Android
Open the camera app and tap the gear to see the settings. Scroll down to Voice control and turn it on. Now you can take pictures with the commands "Capture," "Shoot," "Smile" and "Cheese."
***Edited to add Labels***