Damn Puzzle! (Get it here)
See the Lichess.org user vote of a tactics puzzle before wasting time on it.
How it works.
Whenever you request a tactics puzzle from lichess.org, it automatically sends you the user vote on that puzzle. However, for some reason the website only shows you this information if you are logged in and after you have completed the puzzle. This of course can be very annoying and thus this browser extension allows you to view the rating before wasting time.