From the xcode-users mailing list:
> My app built with Xcode on 10.9 won’t launch on 10.7, but I don’t use any new OS features.
The most likely cause of your problem is base internationalization. Newly created Xcode projects have base internationalization turned on, but base internationalization works only on OS X 10.8 and later.
To support 10.7, turn off base internationalization. Select your project from the project navigator to open the project editor. Select your project from the left side of the project editor. Deselect the Use Base Internationalization checkbox.