Wallpaper Cycler - NuonSoft WallpaperCycler is a powerfull utility to manage all your wallpapers and to automatically cycle between your wallpapers.
Wallcat - Enjoy a new, beautiful wallpaper, every day.
FCorp My Desktop - "ALL-IN-ONE" Desktop Related Tools.
Splashify - Beautiful desktop wallpapers for Mac and Windows
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
Irvue - (previously Unsplash Wallpaper) Gorgeous wallpapers on your Mac.