GIFit! - Quickly turn YouTube videos into GIFs (chrome extension)
Turn Off the Lights - With a single click on the lamp button, the page will fade to dark.
Book Video Club - Quick video summaries of the top business books for startups
SmartVideo - SmartVideo is a tool that offers users better experience on YouTube as it enables users to have better control over YouTube buffering, and playing options.
Wibbitz - Watch video summaries of the news you want.
SliceTube - The Fast and Modern way to cut and download YouTube videos