Xcode 4.2 is the newest update to develop iOS apps. Basically, the most notable change is the addition of Storyboards and ARC.
Thanks to those two new features, I was able to finish the global navigation of a rather complex application under a day. Brilliant! This is a great gain of time and a guarantee that the navigation is bug free.
However, right after I got done, I’ve noticed that applications made with storyboards only run on iOS 5.0. It’s current common practice to neglect iOS 3.0, but 4.0 retro capability is highly wanted as most ordinary users have not made the switch to iOS 5.0 yet. Therefore storyboards are practically useless at this point.
As for ARC, it is fully compatible with iOS 4.3 (which means iPhone 3gs). It is partially compatible (no weak linking) with iOS 4.2 (which means iPhone 3g).
Bottom line, I will start over without storyboards, keeping ARC on and I’ll target iOS 4.2+.
Also, I’ll be waiting for iOS 6.0 to come out to start using storyboards.