I downloaded the mobile app and reached 50 new words which is the limit if you are a free user. Fine, no more new words for today. However, I should be able to review already learned words still according to the app. Unfortunately, when I tap "continue learning" I get a message that tells me I reached the 50 new word limit and gives me the option to either remain a free user or upgrade. When I choose to remain a free user, I go back to the main screen and cannot review words. When I restart the app entirely, I can review one word, and then this happens again and I can no longer review words. Is this a bug or is there another way I can review words in my app?