Screen Cleaner

This is just a small utility app to help people to better clean their phones and tablets. People usually clean their phones or tablets in this way: lock the screen and then clean the screen, it's a little bit inconvienent and sometimes you could only see some dirty dots when the screen is in white background, so I created this utility app to help people to better clean the screen of phones and tablets, user could just press the volume up or down key to toggle the background to white and black to better clean the screen.