AutoWallpaper - Using AutoWallpaper:
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!!
Wallpaper Engine - Wallpaper Engine enables you to use live wallpapers on your Windows desktop.
Pixiv for Muzei 3 - Best Pixiv plugin for Muzei 3
Wallpaper Wizard - Wow-worthy backgrounds for Mac
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads