How to make app compatible with iOS 6 and iOS 7 both and iphone 3.5 and iphone 4 inch

Question

I am developing an app which needs to be compatible with iOS 6 and iOS 7, and also for iphone 4 and iphone 5 supportive as well.

What are all steps that i need to consider while developing such kind of app ? can any one suggest me on this. Thanks in advance :)

Answer 1

If you're a new developer - I would say this is going to be challenging for you.

But off the top of my head:

1. Make sure to use iOS7 APIs only for iOS7 - so no NSURLSession under iOS 6 for example.
2. You will need to design two UIs (One for iOS6 feel and one for iOS7 look)
3. Autolayout should take care of most of the UI layouts for different size screens
4. Since you're supporting the iPhone 4 - run the app on the actual device to make sure you don't suffer performance issues.

Suggestion though: Since you're supporting iPhone 4 and up - why not drop support for iOS6?