Yeah, I'll totally second that. I've learnt recently how to acces directly to the flashcard page with my phone, but an app it's the way to go. There's really good integration between the lessons vocab an the flashcard system, so the logical step it's to actually make the flashcard system a lot more easy to use a readily available.
Is this still in consideration? I think being able to review lesson vocab and kanji during my commute would be one of the best tools that I could have for learning Japanese. I am using Anki for this, but I wish I had access to the lesson vocab (no, not in list form but actual flash cards) offline.