Feature Request - Bookmark/Favorite a Puzzle

[RangerOri]

I'm playing lichess from time to time and I use to play the daily chess challenges or trainings...
I saw a game that the moves really amazed me, and I forgot it's number.

I think it would be great if a user would have a list of puzzles which he can revisit, like a favorite list.

I hope I didn't miss this feature, cause I didn't find it in the mobile app.

An upgrade could be having a list of puzzles or entire games, if it's not too much data to hold.

I might help implement it, I'm a software engineer if any help would be needed.

Thanks in advance.