John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
AutoWallpaper - Using AutoWallpaper:
FCorp My Desktop - "ALL-IN-ONE" Desktop Related Tools.
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!!
Wallperizer - Wallperizer is a desktop wallpaper changer.
Pixiv for Muzei 3 - Best Pixiv plugin for Muzei 3