SmartWindows.app - Auto arrange all your app windows, whether on one screen or many with a single click!
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
Accelerated - Online community to break into tech & VC
Muzei - Muzei is a live wallpaper that gently refreshes your home screen each day with famous works of art.
VC Starter Kit - Everything you need to look like a Venture Capitalist
Variety Wallpaper Changer - Variety is a wallpaper changer for Ubuntu which is featureful, yet slim and very easy to use.