One of the first things you do in the book is create iphone application and then modify it to a universal application for iPhone/iPad. It covers the basics of building a “hybrid app”, but you can get a whole lot more sophisticated by Using Runtime Checks to Create Conditional Code Paths. By creating conditional code paths depending on which platform the app is being run on, the customization of the user experience is endless. If your application is going to be functionally different, but conceptually the same, I would recommend building the iPad app separate from your iPhone app. The iPad Programming Guide from Apple is a great thing to read….little tip if you have an iPad check out the Developer Documentation on the iPad using Mobile Safari…The formatting is setup perfect for a reference.
PS. it would be great if the authors would add at least some pointers for making universal apps, and how to ensure the best performance for the user on both platforms. Maybe in the fit and polish chapter?