IOS6 introduced the super-handy native flashlight. During the winter months I use this every night after work, when I go out back and see if the hens have laid any eggs.
With the migration of the iPhone's power button down from the top of the device and into a place where I accidentally hit it pretty much every fucking time I pick the fucking thing up, turning the flashlight off has become a serious pain in the ass. "Whoops, you powered the phone off. Press the Home button, slide to unlock, enter your password, swipe up from the bottom, and tap the flashlight-shaped thing." This is hard to do one-handed or while carrying an egg or two, so I wind up sticking the phone in my pocket with the light on.
Today I learned that since my camera is available from my iPhone lock screen, all I need to do is hit the power button again and swipe up from the camera icon in the bottom right corner. As soon as the camera app starts, the flashlight turns of