CONV. - Convert YouTube video to MP3, GIF or MP4
you-tldr - Get the tldr of any YouTube video in seconds
Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
SliceTube - The Fast and Modern way to cut and download YouTube videos
You-Get - Command-line utility to download media contents from the web
GIFit! - Quickly turn YouTube videos into GIFs (chrome extension)