I'll have to give it another try in a few days when I have a decent chunk of time to get my head around Xcode.
Meanwhile I have some questions:
Where is AppDelegate.m located? I found something with a similar name but it wasn't simply called AppDelegate.m, and I'm meant to add "#import <Chartboost/Chartboost.h>" to it.
"Initialize Chartboost in your didFinishLaunchingWithOptions method" <-- How and where do I do this part?
In fact, is anything from part 6 onwards in this article stuff we have to do? I didn't have to do anything with Android and iOS is all new to me.