Thank you for the feedback. I agree with everything you say. Working hard to make it better. Several of your suggestions are already on my "hot list" for the very next update, which (I hope) will be weeks rather than months away. A couple comments:
Fonts: It was hard to tell in advance how big the download size would be after apple encrypts the app (impacts compression). Ends up we have some good breathing room, so next update we'll put in more fonts (suggestions are welcome, but know that we use .otf). We plan to allow users to import their own fonts (otf) not sure yet though if that will make the very next update, but it is easier than it sounds.
Color: Yea, that color selector is something we happened to have. I want a color wheel.
Page Turn response: This is a hard one, and you'll see similar issues in PDF related to interaction freeze while re-rendering. I think we can do better, but probably not a quick fix.
Night Mode: totally ghetto inverted greyscale. images look like negatives. We had very hard arguments about whether to pull it. But it actually really helps for night reading. Another one that will take some time. Though I think we might be able to address the flashing and color settings related issues pretty quick though. When we do, I think we should pull out the inverted mode.
Thanks again for your feedback. We really do want to make it a great app.