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!!
Wallcat - Enjoy a new, beautiful wallpaper, every day.
Artpip - Artistic wallpaper for your desktop, refreshed daily.
Splashify - Beautiful desktop wallpapers for Mac and Windows
AutoWallpaper - Using AutoWallpaper:
Irvue - (previously Unsplash Wallpaper) Gorgeous wallpapers on your Mac.