John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
WLPPR - Beautiful mobile wallpapers made from satellite imagery
Unsplash Wallpaper - Gorgeous wallpapers on your Mac
Walllpaper - Turn Dribbble shots into backgrounds for every iOS device
Wallcat - Enjoy a new, beautiful wallpaper, every day.
Haaazy - Premium collection of high-quality hazy wallpapers