Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
you-tldr - Get the tldr of any YouTube video in seconds
Yout - YouTube to Mp3 Converter
tubecut. - The only YouTube downloader allows you to trim specific time
You-Get - Command-line utility to download media contents from the web
GIFit! - Quickly turn YouTube videos into GIFs (chrome extension)