Muzei - Muzei is a live wallpaper that gently refreshes your home screen each day with famous works of art.
Wallpapers - Wallpapers is a leading personalization application by Google LLC that make the most of your display with beautiful wallpapers and advanced features.
Variety Wallpaper Changer - Variety is a wallpaper changer for Ubuntu which is featureful, yet slim and very easy to use.
Backdrops - The only wallpapers you'll ever need. Say hello to Backdrops.
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
WallpapersCraft - HD & 4K wallpapers