Display name is what appears below the app icon on your idevice home screen. By default its same as your project name in xcode. If you would like to change your app name or add spaces between words, follow the steps below –
1. Edit the “info.plist” file of your project, you’ll find it under the “Supporting Files” group in your project navigator.
2. Change the value for “Bundle display name” key to the new app name. Save the info.plist file.
3. Delete the old app from simulator or device if you are using any for testing your app.
4. Clean your build, goto “Product menu -> Clean”
5. Rebuild your app again. You will now see the new app name on the home screen.