New feature? Scorecard is here.
I've just got this for the first time:
Several have asked for something similar so this is great to see :-)
Absolutely awesome. I found that by looking at the review page, you can even go and leave comments on any task (even ones you got right) by copying and pasting the exact words of the task into the search field of the discussion page. It sounds complicated but just takes a few seconds.
Hopefully, I will get this feature soon and I can add it to my Duolingo Notes app. https://www.duolingo.com/comment/2976444$from_email=comment&comment_id=3146674
Sometimes DL does 'test groups' where they will test a feature with one group of users for a set period of time (usually around a month) and then decide if the feature is usefully enough for everyone to have it. If they decide not to use it, those in the test will have the feature taken away.
I did a bunch this morning without seeing it, and then after seeing this post I did another one and poof! it was there. Hopefully it's something you'll see soon and not just rolled out to a test group. That said, I do seem to get a lot of the test features for some reason. My Duolingo always has stuff coming and going :)