Here are some points which I would like to suggest:
- Folder structure: please, this would improve INSANELY the app;
- Larger page formats: sometimes I want to study something that is big, and the classic index format is somewhat limiting. A full page format would be awesome;
These are the main suggestions.
There are one more that I would consider a nice-to-have:
- Sequential reveal and/or multiple-page cards: ok, I agree this is somewhat complicate, so I'm going to explain further: when I am studying a math proof, for example, sometimes I want just the right next step, which hopefully triggers my mind. The ability to make these steps would help in the study of subjects that have this link-style of knowledge.
Now, I have to say: the Kyoku app is already the best on its niche, with its clean interface and good writing style and response, and the price is a real bargain. I payed for it and would pay again for those updates. Heck, if you made these suggestions become real and asked only me for $29.99, I would pay gladly.