Prevent your Android screen from entering sleep mode, with Backlight Manager
Backlight Manager is a free Android app that can keep your screen from entering sleep mode without you having to change anything in Android settings.
As is normal, if you don’t use your smartphone a minute or so, the screen enters power save mode to save battery. However, sometimes you may need your screen to remain alive even because you don’t care for power, if you are charging the phone, or for any reason.
Backlight Manager includes an easily accessible option of keeping your screen on forever, until of course you disable this option.
Backlight Manager seems to work flawlessly with any Android phone. A nice options it provides is an auto start mode as well as automatically being activated when you charge your phone, in case you need your screen always on when you don’t need to save power. The app is even able to activate a custom brightness level when it is on! Of course, a timeout mode is also provided, letting you return to normal power off mode after some time.