Codes / Scripts that will not work on iOS

Hi, I’m currently using the regular unity on PC (the one that comes free) and I want to try developing an app on iPhone. Is there any codes, or functions or any changes that I should be aware of when going to iPhone development? If there are lists that you can provide me, if would be helpful.

You will need a Mac and a mac developer account and a lot of patience. And read this: http://docs.unity3d.com/Documentation/Manual/iphone-GettingStarted.html
Amazing what they just give you in the docs