You need to do the following steps for adding this widget or another one to your Android device:
1) Long press on an empty area of the home screen until a menu will appear.
2) Now you will see an screen with a title like Add to Home Screen with some options: Shorcuts, Widgets, Folders and Wallpapers.
3) Choose the Widgets option.
4) Choose the Flag LCD Clock Widget option.
5) A new application will open. Here you can setup the brightness of the active/inactive LCD. Set up it as you like...
6) Once finished setting up press install and the widget will appear in your home screen.
Once installed if you long press on the widget you can move it throw the screen or delete it.
If you press it, the configuration application will appear again for adjusting the brightness of the LCD.