I want to change the name which is displayed below the app icon on the iPhone screen. I use Xcode 4 and I have one target with keys:
In Xcode 4, select your target, "Info" tab, and set the "Bundle display name" field to the name you want (i.e. "MySuperApp"). This is the simplest, pain-free solution.
All other answers described here do not address the original posted issue: "I want to change the name which is displayed below the app icon on the iPhone screen." The upvoted answers of: Woody, Jay, and youshunei are OK but they will all change the displayed name AND either:
A) change your App Bundle Identifier and cause an incompatibility between your app and the Bundle Identifier you registered with the Apple Provisioning Portal (which is a problem if you have already distributed your app or intend to submit the app)
OR
B) result in scheme issues that others have mentioned (i.e. needing to delete/re-create existing schemes)