If you look at "Japanese lessons" in the resources tab of the menu on the left (the corner button that looks like 三) you can see what's technically covered grammar-wise. But it goes as long as you want it to go, they keep adding to it, you don't "finish" renshuu, you learn enough Japanese that you don't need an app or you get bored of this one and do something else.
renshuu covers more grammar than what's in the Japanese Lessons - we have grammar entries and quizzes for advanced-level stuff. We just don't (yet) have the lessons written for them.
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