Here is a quick list of a couple of sites I discovered recently, and a couple that I have been following for a while that are all fantastic ways to keep up with what is happening in iOS and Mac app design at the moment as well as being great sources of inspiration for your own apps.
Interested in getting your team up to speed on iOS? Check out our in-house training course.
We also run iOS Dev Weekly, a free weekly email with 10 or so links to the best blog posts and articles on iOS development for the week. If you are interested in iOS development then it is likely that you will find something of interest in iOS Dev Weekly each week. You should subscribe!.