Developing for the larger screen of the iPhone 5 actually helps developers, because it gives us more screen real estate. Before, when we had to develop for the smaller screens, things might become crowded in there. We would have to shrink our table view and you’re not able to view as much because you would have to fit a couple of buttons on the screen. Things were very tightly spaced and you would have to worry about people who have big fingers. You would have to worry about things like, “How big do I need to make a button so I can touch it without accidentally touching the one next to it?” The bigger screen allows developers to breathe a little bit; to spread things out and space things nicely. So, from a design standpoint it’s actually beneficial to us as developers.
However, there are some downsides the screen adjustments. Before, in the “old days” as we used to say, we only had one set of images for the device. Then, when the retina screen came out, we had two sets of images for each control- the low resolution version and the high resolution version- but still only had to code one view. Now we have to keep track of more resources. With wallpapers and backgrounds, you may have to keep track of a third image. Or, you may have to create a whole new view and add code.
As you can see, while this change does free us up and provides extra flexibility from a design standpoint, it does make more work for developers from a development and coding standpoint. Still, IOS 6’s new layout feature does take some of that load off. You can now build your app in such a way that it will scale to any device. If you want to support older operating systems, however, the extended method is the only way to go.