Mobile screen sizes on the whole are becoming more similar, and that’s a good thing. But it also means that we can’t just treat screens in the 5.5” range simply as a scaled-up version of a smaller phone. Grips completely change, and with that, your interface might need to do so, as well. I think prototyping will become even more important. So if you haven’t jumped on that train, now’s the time. (PS — I’m launching Xcode for Designers next week, which teaches designers how to build interactive prototypes in Xcode in less than a week. It’s chock-full of videos and has a really great pre-launch discount running right now. Get on the list if you’re at all interested.)