Combining Apps Into Universal Easy? iPhone/iPad

I am about to begin developing an app开发者_开发技巧 and have never worked with universal binary. Is it possible to create them both individually and then merge them is needed later?

Or is that out of the question? It is pretty important to decide from step one whether I need to go universal or not?

Also whats your expericne been with universal apps? Has it been an easy experience, or troubling?

Thanks.

---

It's very easy and works out of the box.

The template has two app delegates and two MainWindow xibs, one per platform (iPhone/iPad). You can also factor common code into a shared app delegate.

When you start adding code, usually the Model part is the same code, the controllers are part the same and part different depending on how the GUI behaviour differs, and the View part is the only one which is really different - You would usually need two XIBs per view controller, one per platform.