LiChess Tools, by Siderite

This extension adds a lot of extra functionality to the https://lichess.org web site.

Main features:

• Extended Interactive Lessons allow you to play ALL variations
• Explorer Practice allows you to play against the moves in Opening Explorer, essentially helping you train against any rating bracket on the Internet or a specific opponent
• local computer analysis chart when no server one exists, even when not logged in
• Enhanced PGN Import in Analysis board allows you to merge multiple PGNs into a single one (lichess limitations strip down the comments, but I am working on a solution). This helps you quickly collect a player's repertoire and maybe save it as a study Interactive Lesson, simulating their play. Then you can export the current analysis moves into separate lines as well, or just copy a single branch as a PGN.
• See evaluation of possible moves of the selected piece in analysis
• Automatic detection of interesting/brilliant/good/best moves
• a PGN editor supporting a lot of operations and accepting tens of megabytes of text
• Mobile device features (for browsers that support extensions on mobile, like Kiwi), including drawing arrows and circles on mobile, scroll/zoom lock while playing, etc.
• Change the friends box into a menu or a button, live update Friends page,
• Sound and voice notifications where players you follow start playing (with mutable option per player)
• TV enhancements: Current games section for players you follow and streamers, menu to go to previously opened games, previous two games in player TV just like in category TV