This application is useful before bedtime.
You can see 'today quote' in notification panel also.

You can have cinema etiquette with this application.
Make your screen darker with not pause a game.
Reduce your battery.

Drag the red dot in application.
When this screen is totally darken, if you press this, then this screen is going to bright.
Long press the red dot will close the application.

Please close the application BEFORE installing new applications to avoid installation errors.
Because of Android policy, install button would not pressed.