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