Question: I have an existing working app, created on Xcode 5, built and designed for iPhone 5 , 5s…( iPhone 4 inches).   
 if i am to make it supported to iPhone 4 (3.5 inches) all the design would be messed up… should i create a mew storyboard just for iPhone 4/4s and in the main page test whether it's an iPhone 4 or 5 and load the appropriate storyboard? or is there any feature that could just make all the design fit the screen of an iPhone 4 ?? rearranging all of the design could take lots and lots of time
Many thanks

Answer: 
Auto Layouts is a great thing. I would start with this tutorial
<http://www.raywenderlich.com/50317/beginning-auto-layout-tutorial-in-ios-7-part-1>

Once you implement auto layouts you can see see how your screen looks like for specific iPhone version even without running the app. You can just switch the view in storyboard by clicking "Apply form factor" button.
Use `Autolayout`to manage the screen size