Thank you for the feedback. I’ve deliberately not attempted to teach grammar or pronunciation with it since I’m aiming for people who already understand those things (i.e. intermediate learners) but who need help to go from intermediate to advanced Japanese (mostly a matter of building vocabulary) and for which there do not seem to be many educational resources. So right now my foremost goal is to get more books published to broaden the vocabulary presented in the books. Hope that explains its approach!