Hello:)
I love quizlet, because I can make study sets and review me lessons and studies by myself. I advise all studiers and teachers to use it, you could use it to study all subjects (language, history, botany etc.) and also if you are a teacher, you can check your students' progress, but you have to pay.
Another thing, it can show you your weekly streak like in the picture:
Link: https://quizlet.com/latest