Hello everyone! 
I've added a new "book" icon on the Learn and Review pages.
On a course's review page, when "Level up" is selected as the test type, the icon shows which testing methods have words ready to be reviewed:
Hovering over the icon displays how many words are ready to be reviewed:
On the learn page, the icon indicates which review methods you've used before. For example, in this screenshot, I've already learned 34 words in the Word -> Definition direction but haven't learned any words in the Word -> Pronunciation and Definition -> Word directions.
