check https://bitbucket.org/braunbearded/youfaster/src/master/README.md

Listen to only the audio on YouTube without loading the video.

Help you easier to download files from anonfiles.com network, and can download video from porn site..

Script to automatically like Youtube Videos Opened in Browser

Scrobbles the currently watching YouTube video to last.fm, optimised for YT-Center

Download every YouTube video you want and you can download them as Full-HD MP4, FLV, 3GP formats. Easy & Fast!

Redirect Youtube Links to Embed Links

Removes Youtube Videos where channel and name video add to black list.

Show YouTube thumbnail picture by button, near likes buttons.

Colored header for channel based on its cover image.

Removes video and plays mp3 on youtube.

Create a cinema feel while watching youtube videos.

YouTube with more freedom

Scroll through comments while video is still visible.

Forces the Youtube UI to use the old interface (which is secretly still available)

Remove all shorts

Custom Youtube Theme

Automatically increase volume to 100%

Block ads on Youtube

Hide watched videos on YouTube

opens youtube videos in TV(https://www.youtube.com/tv#/) mode. other pages like http://www.youtube.com/feed/subscriptions will open in their default desktop view. TV playback seem to be only avaliable to MSE compatible browsers like latest stable Chrome or Nightly Firefox

Buffers the video without autoplaying and puts it in HD if the option is on. For Firefox, Opera, & Chrome

Buffers the video without autoplaying and puts it in HD if the option is on. For Firefox, Opera, & Chrome

Adds a button that opens up the current video in embedded mode, for semi-fullscreen viewing