A free program for Android, by AppzStudioK.

Double Tap Screen On and Off – Shake Screen OnOff is an amazing tool for all users. It’s a handy utility that is designed to work with your Android device. It allows you to set the double tap time and also the number of times that it will be activated. Moreover, you can use it to turn off the screen as well. There are various settings available in this tool that you can change according to your need. 

This app is designed to be very easy to use and understand. All the users will be able to use this app with no problem. It has a simple interface that you will be able to understand in a second.