1) I clicked "Get started" and then created an account. It took me back to the home page and asked me to "Get started" again. I clicked "Get started" again and it again asked me to create an account although I am already logged in.
2) I have a 5yo early reader and I thought this would be good but I don't understand what the "Levels" are.
3) I expected that clicking the book's preview page would have the same effect as clicking the preview button.
4) There is a typo in the alligator book on page 6
5) "Hot Car" is a weird story line for a kid lol
6) The dollar symbol says "Acquire book" when I hover over it. That doesn't fit with what I expected. I thought it should say, "Buy book" since you are showing me a currency symbol.
7) I've been on the site for 3-4 minutes now and I don't see or know how the "customizable" aspect works.
8) I previewed 5-6 stories and none of them appealed to me as the parent of a precocious 5yo boy.
I hope this feedback helps and I wish you good luck!