Wallpaper Cycler - NuonSoft WallpaperCycler is a powerfull utility to manage all your wallpapers and to automatically cycle between your wallpapers.
WLPPR - Beautiful mobile wallpapers made from satellite imagery
Splashify - Beautiful desktop wallpapers for Mac and Windows
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
Wallpaper Wizard - Wow-worthy backgrounds for Mac
Wallcat - Enjoy a new, beautiful wallpaper, every day.