Like the screen tap off feature of the LG G2??? I figured out a way to do it on other devices.
What is required: A launcher such as Apex, Nova or any other that allows gestures and desktop taps. Usually requires the purchase of the premium version. And the app called Screen off and Lock.
-Install the Screen Off app
-Go into your launcher settings where you can change desktop behavior. I am going to use Apex as an example. It is behavior settings.
-Choose desktop double tap
-Choose launch app
-Select the Screen Off app
Now when you double tap your screen the screen will shut off just like the tap tap feature on the LG G2. Doesn't work for screen on. But if you have one of the new Motorola phones when you pull it out of your pocket the unlock choice will be there already. No need to touch the power button at all.