Wallpaper Tray is one of those cool apps that just does its thing without needing much assistance. It adds functionality to the desktop by allowing one to automatically change wallpaper on startup or at timed intervals. While this kind of thing is not new, this is by far the best applet I have found in this category. It sits nicely in the toolbar where you can configure it by right clicking. It will also show which wallpaper is selected and is an easy way to change wallpaper when needed. The only quibble I have is that it doesn’t appear to have the ability to set different wallpapers for different desktops, which would have been nice. Nevertheless, a good piece of work from dark project studios. Oh, and before I forget, there is a great set of free darkwave wallpapers if you’re looking to add some mystery on the desktop.
sudo apt-get install wallpaper-tray
http://www.darkproject.com/