Question

What needs to be changed to make an iphone app compatible on the ipad?

I know the icons etc must be different etc. but in terms of code?

Answer 1

What needs to be changed to make an iphone app compatible on the ipad?

You need to provide iPad sized views.

Code level changes greatly depend on the app and how you want to design the iPad app. In the simplest case you would need to simply provide some new xib files for iPad specific views. Barring that you would have the same controllers with different xib files, plus some branching code in your controllers to manage some iPad specific features and layouts. Or you may decide you need more types of differences and need to write new controllers as well.

But from the point of view of the developer, the iPad is simply a giant iPhone. Providing views to match the larger screen is the technical issue, and that is easy. But from a usability standpoint your app might end up much different since designing interfaces for a 3.5 inch screen is much different than for a 10 inch screen.

So if you new UI for iPad is a direct one to one mapping to an iPhone app then this is easy and you simply load an iPad xib for all your existing controllers. If you design to take advantage of the larger screen in ways that diverge from the iPhone app, then code level changes will be required to handle the differences between the 2 UI’s.