After three major news outlets confirmed that Apple was ordering larger smartphone displays last week, the 4-inch iPhone theory is quickly going from rumor to fact. It seems like everyone is giving into the idea, including developers.

GigaOM recently polled a handful of high-profile iOS app-makers regarding the prospect of a larger-screened iPhone. And the general consensus seems to be that they aren’t too worried about it causing any major headaches…

Lenny Rachitsky, CEO of Localmind:

“We haven’t put a lot of thought into it yet, partly because we assume Apple isn’t going to pull an Android and fragment the device market unnecessarily. if they do, they must have a really good reason to do it, and we’re confident they’ll provide tools to make it easy to migrate. The last thing they want to do is put more friction in front of developers.”

And Localmind’s lead iOS developer, Nelson Gauthier, agrees:

“Apple often changes the requirements for iOS applications but they usually give developers fair warning and decent tools to accommodate new devices. The transition to Retina display and iPad were both relatively straightforward.”

These are actually really good counter-arguments to the notion that Apple would not change the iPhone’s display out of fear of fragmenting the platform.

Apple knows how important developers, and their 600,000+ apps, are to its ecosystem and the overall success of iOS. It’s not going to jeopardize that by making an iPhone with a mutant display that no one can work with.

If these 4-inch screen rumors materialize — and it’s certainly looking like they will — you can bet that Apple has made the needs of its developers a priority.