This is a widget app. keep screen ON, and Stop screen sleep. Special permission does not need. There is no need to change the OS settings. It is useful in application development : ). It seems that permission of autostart permission is necessary for some terminals, it is under investigation. Autostart - security center - permissions - autostart.
JOJOAGOGOGO is the creator of Keep Screen On ~Widget~ which can be found in the Tools category. The most recent update of the app was released on Sep 23, 2016 and this application has been set up by over 5K users. Users rated Keep Screen On ~Widget~ 3.8 on Google Play.
This application displays adverts. Take the opportunity to download the installer of Keep Screen On ~Widget~ 1.3 for free and check out users' reviews on Droid Informer. The app is compatible with Android 4.0 and above. The download of the app is safe and secure.