John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
Live GIF - Convert live photos to GIF
Muzei - Muzei is a live wallpaper that gently refreshes your home screen each day with famous works of art.
Copdate - Reserve a spot for limited sneakers at a local retailer
Variety Wallpaper Changer - Variety is a wallpaper changer for Ubuntu which is featureful, yet slim and very easy to use.
Layout by Instagram - Combine multiple photos into a single image