Nick Arnott at Neglected Potential has a great Mind Map up showing all the different combinations for iOS testing

I had previously posted about a mind map for getting started with mobile testing that I had come across on the Ministry of Testing website. What I was really hoping to eventually see was an iOS specific one, which I’m happy to say we now have. Bernard and I have put together this mind map for testing iOS.

He covers off top level items of Hardware, Networking, Data, Software, Audio/Video, Functionality and UI. It's not an exhaustive list - because only you can make an exhaustive list for your app - but it's a great start for all the various combinations that should be covered. Plus, he's got the Simplemind files there, so you can add your own stuff.