Wallpaper Engine is an application allowing you to use dynamic & animated wallpapers (such as scenes, videos, web or even applications) for your desktop.
You can create your own animated wallpaper as well.
It costs only 3,99€ but I believe this is a must-have for your computer. I highly recommend it.
Since it is only available on the Steam platform, you will need to create a Steam account if you already don’t have one (it’s free).