If you want to play prank on your friends without doing anything crazy, you can download this Chrome extension. With this tool you can change some of the settings and the behavior of a website or browser. You can make the scree fade, blur, or rotate. Download this first in your browser to try which prank to play on your friend. You can then install it in their browser but make sure that they would not notice.  It is very simple to use and there are many settings that you can use.