We can go with the following approach to get iPhone version of iPad xibs already exist in the project. With this approach we no need to create a new xib and manually add all the subviews.
1. Xcode recognises the iPhone version of a XIB if the suffix is ~iphone (lowercase only) and iPad version if its ~ipad. If no suffix exists then it will consider it as an iPhone version. Lets suffix all the existing xib names with ~ipad.
2. Duplicate all the xib files and open them in TextEditor and do the following.
change “com.apple.InterfaceBuilder3.CocoaTouch.iPad.XIB” to “com.apple.InterfaceBuilder3.CocoaTouch.XIB”
change “iOS.CocoaTouch.iPad” to “iOS.CocoaTouch”
change iPad size (width=”1024″ height=“768”) to iPhone size (width=“320″ height=“568″)
3. Add the xib to the project and open it on Xcode.
4. Select the root view and go to the attributes inspector.
5. Change the orientation to portrait and size to Retina 4-inch Full Screen.
6. Adjust the frame of all the subviews.