I am using Xcode 5 in a newly created app and when I just create it I go for the run button e click on it, then the project gets built but it does not show in the iOS Simula
If you added new storyboard then you have to check following points.
1) In your plist file check value of Main storyboard file base name (iPad) or (iPhone) should be matched with your storyboard file name (do not add extension .storyboard)
2) In storyboard there should be one view controller which set as Is initial view controller
3) Clean and build your project. :)