Becrux Wally - Wally is a Qt4 wallpaper changer, using multiple sources like files, folders, FTP remote folders, Flickr, Panoramio, Ipernity, Photobucket, Buzznet, Picasa, Smugmug, Google, Vladstudio and deviantART images. Now it's available in many languages!!
DesktopSlides - DesktopSlides is a light and user friendly desktop wallpaper changer for windows.
Artpip - Artistic wallpaper for your desktop, refreshed daily.
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
AutoWallpaper - Using AutoWallpaper:
Kuvva - Kuvva is the source for beautiful wallpapers.