The author seems like a genuinely nice guy; the emails you get from him show that he is really doing this for the best possible reasons. However, the current features cannot justify the price. For $90 you basically get a tree map. The flash cards are more than simple, there's only text entry. The UI is more than simple as well. I would really like to love this product but this is just not enough. Compared with what other deals provide (in terms of how many features, and how polished they are) this is barely worth $15 at the current stage but more importantly it's not worth my time. I am getting a refund, sorry.