Really? I have to say that the book is not quite ready, in terms of a few things I’ve identified. Importantly, the book does not do well for “following along and coding”. If you want to present the book in terms of “here’s a completed section, lets analyze some choice bits” that’s fine, but I believe the promise is “follow along on your own computer and see the result” and that is not ready yet.
I also think some important concepts are not fully introduced; for example the Storyboard API.