This is my lack of experience, but how does a blind person launch the app and find the correct button to push? I have toyed around with the Accessibility Features on the iPhone, is there a mode that will speak out what you are tapping on?
Yep. We have optimised quite a lot for VoiceOver. The graphical part of the UI is quite boring for the blind :)
You should try VoiceOver and the gestures that come with it, it's mind blowing how well it works. I've found plenty of usability improvements that are really easy to make so that VoiceOver works flawlessly in apps I've worked on.