Variety Wallpaper Changer - Variety is a wallpaper changer for Ubuntu which is featureful, yet slim and very easy to use.
WLPPR - Beautiful mobile wallpapers made from satellite imagery
Splashy - Breathtaking, auto changing wallpaper app for macOS, Windows, Linux, iOS & Android
Wallcat - Enjoy a new, beautiful wallpaper, every day.
Wallpaper Wizard - Wow-worthy backgrounds for Mac
Muzei - Muzei is a live wallpaper that gently refreshes your home screen each day with famous works of art.