My existing app has two Storyboards (for iPhone and iPad), and it supports iOS7+. I am now planning to convert it to one storyboard using Autolayouts and Size Classes, but I have few confusions:
What will the size of the images? For instance, right now without Size Classes and Autolayouts, I ask designer to slice images for iPhone5, and iPad and make them @2x and @3x respectively. But for Autolayouts, what size they will have to slice i.e what screen size will they choose and then will give me images accordingly for @2x and @3x, i.e what universal screen size? For instance, I ask them to give me a background image of screen size. What size will they give me? From what I understand, it should not be iPhone specific or iPad specific as the app will be universal.
I am aware of the fact that Size Classes support iOS8 onwards, so what about iOS7? I will have to do things programatically for iOS7? Will I have to use device-specific images or can I use universal size images for iOS7 as well?