GifRun - GifRun provides easiest way to find and create animated GIFs from YouTube, Video, Images or Vine...
You-Get - Command-line utility to download media contents from the web
CONV. - Convert YouTube video to MP3, GIF or MP4
Turn Off the Lights - With a single click on the lamp button, the page will fade to dark.
Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
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.