Awesome
Desktop Wallpaper Switcher
A cross-platform (Windows / Mac OS X / Linux) tool for cycling desktop wallpaper at a regular interval. Has a wallpaper list manager and a simple image browser for quickly sifting through your heaps of wallpapers (and deleting those you don't like.)
Building and running
Should be straightforward for Windows, as long as you have Qt installed (works with both Qt 4 and Qt 5, x32 and x64).
Download
Only Windows version is available for now (Win Vista, 7, 8, 8.1; 32 and 64 bit compatible).
<a href="https://github.com/VioletGiraffe/desktop-wallpaper-switcher/releases/latest">Get the latest release for Windows</a>
Note
There's no implementation for setting the wallpaper on Mac and Linux yet, the rest (UI and cycling logic) should work.