InvidioMe - Convert any YouTube Links and Videos to Invidio Links
PeerTubeify - On YouTube, displays a link to the same video on PeerTube, if it exists.
Privacy Redirect - Redirects Twitter, YouTube, Instagram & Google Maps requests to privacy friendly alternatives.
Untrack Me - Surf the web, free from tracking
FreeTube Redirect - Redirects YouTube links to FreeTube.
Invidition - A WebExtension to redirect ALL YouTube and Twitter requests to their alternative interfaces.