ArtPlus ePix wallpaper calendar - ArtPlus ePix wallpaper calendar is FREE software!
National Geographic for Muzei - National Geographic pictures for Muzei
Variety Wallpaper Changer - Variety is a wallpaper changer for Ubuntu which is featureful, yet slim and very easy to use.
Pixiv for Muzei 3 - Best Pixiv plugin for Muzei 3
AutoWallpaper - Using AutoWallpaper:
Muzei - Muzei is a live wallpaper that gently refreshes your home screen each day with famous works of art.