Features

incomplete list.
missing short description (to integrate in tooltips) and preview screenshots, .gif's, videos or longer descriptions

Player / Playback features:

• Video Quality

• Auto-Fullscreen

• Fixed Volume or disallow Loudness Normalization

• Fixed Playback Speed

• "Repeat" button for Player

• "Screenshot" button for Player

• "Popup Player" button for Player or PIP Picture in picture player

• "Rotate Video" button for Player

• Forced H.264 Video Codec (speed up)

• Video Autoplay Off

• Ads only on Subscribed Channels

• Disallow ads inside player

• Disable 60fps

• Disable Subtitles

• Up Next Autoplay Off

• Mini Player

Player Appearance:

• Player Size
• Forced Theater Mode
• Player Color (timeline/progresbar)
• Transparent Background
• Header style * Monochrome YouTube Logo
• Hide Cards, Endscreen, Annotations

Video Page Appearance

• Hide Related Videos, Details, Views, Likes or change their styles
• Show video age
• Show channel video count
• Change style of "Description", "Comments", "Footer", "Livechat", "Playlist" and "Related videos"

Themes:

• "Black", "Plain", "Desert", "Dawn", "Sunset", "Night"

General:

• Night Mode Schedule
  • Bluelight filter * Dark Theme * Dim Filter
• Set Youtube Home Page
• YouTube Legacy (old Version)
• Disable "Scroll for details"
• "Scroll to top" button
• Prevent Closing YouTube
• Squared User Images
• Disable Moving Thumbnails
• HD Thumbnail

Playlists:

• Autoplay
• Reverse
• Repeat
• Shuffle

Channels:

• Default Channel Tab
• Trailer Autoplay
• Hide Featured Content

Set Shortcuts / Hotkeys for:

• Picture-in-Picture
• Video Quality
• Play / Pause
• Stop
• Next Video
• Previous Video
• Seek backward 10 seconds
• Seek forward 10 seconds
• Increase Volume 5%
• Decrease Volume 5%
• Increase Playback Speed
• Decrease Playback Speed
• Go to Search Box
• Activate Fullscreen
• Activate Captions
• Like
• Dislike

Volume Mixer:

• Set different volume for each Youtube tab