Whenever I make a new file in xcode, it puts something like this at the top of the file:
// Copyright __MyCompanyName__ 2008. All rights reserved.
As of Xcode 6.1.1 this can be changed by clicking on the main .xcodeproj file in the project view (the blue one). The right panel has a field called 'Organization' that will be used for the copyright template. This panel may be hidden, and can be made visible with a button in the upper right corner.