Android: Back in the day, Google added a neat little animation to stock Android that would make your screen look a bit like a CRT when you turn it off. While that's getting phased out, Xposed allows you to bring that back, or even it to something else entirely.
As XDA points out, despite the name, the module actually allows you to change both the screen on and off animation. It comes with a preset selection of animations, and you can adjust the speed at which they play, as well. This is just one of the many ways you can tweak your device with Xposed, so be sure to check out our full guide here.