After install there is new App Icon - EasyOff. When you tap it for the first time, app requests Device Admin right. If you grant it, the second and other time you tap it, device goes to sleep mode, as you pushed the power button.
Thats all. NO ROOT NEEDED.
Do you want to support developer ?
BitCoin Wallet: 16Xevan7YoV4eayrFGMPG79sNCVtH31uN8