A Material Design Style Android Night Mode app.Night Mode app can reduce the brightness further,Night Mode can app can also protect your eyes from the hurt of the bright phone.You can also set image you like for all apps. Such as browser,messagesql_injectionso on.

Make sure that third-party apps are allowed on your device: go to Menu->Settings->Security-> and check "Unknown Sources"

Tap the APK file. Allow the app any required permissions it asks for. Then, at the bottom of the installer window, click INSTALL.

You'll see a confirmation the app is installed. Now you'll see the app available in your list of installed apps.