The problem I have with most iOS material is that it's either too simple, or too advanced, often leaving no room for those that understand the concepts but need

The problem I have with most iOS material is that it's either too simple, or too advanced, often leaving no room for those that understand the concepts but need help connecting the dots between the easy and the advanced. Provided the OP actually knows what he's doing, and there's no reason to doubt that, I'm glad to see him doing this, as I believe that the more material on the market the better. I like learning from different teachers, even if they cover the same thing. That said, this was a bit pricey for my tastes, but that's only because I've spent so much prior to today.