To convert Storyboard from iPhone to iPad do the following steps:

1. Duplicate your iPhone-Storyboard and rename it to MainStoryboard_iPad.storyboard
2. Close Xcode and then open this file any text editor.
3. Search for targetRuntime=”iOS.CocoaTouch” and change it to targetRuntime=”iOS.CocoaTouch.iPad”
4. Change the code in the MainStoryboard_iPad.storyboard from: <simulatedScreenMetrics key=”destination” type=”retina4″/> to <simulatedScreenMetrics key=”destination”/>
5. Save everything and reopen Xcode -> the iPad-Storyboard contains the same as the iPhone-file but everyting could be disarranged