iOS: Universal App - Release as iPhone only
In the application's Build Settings change the Targeted Device Family to iPhone, instead of iPhone/iPad.
In the latest xcode you can do this by summary screen too.
Thanks
It's not possible to only release the iPhone version via iTunes Connect, but you can set the Target Device to iPhone-only for the first version and it'll only be released for iPhone/iPod touch.
You need to make two changes. First, Set the Target Device Family back to iPhone. Second, in the info plist remove the Main nib file base name (iPad) entry. If you don't do that last step it will run as though it was an iPhone app (small view port with 2x button) but your iPad main window and delegate will be triggered.
Here is a more details post with some images for illustration:http://www.fullboarcreative.com/labs/2012/04/20/tip-going-from-a-universal-to-single-device-app/