This is just a quick recommendation to a blog post from my friend Oliver, writing about how to implement Doxygen in Xcode and automate it.
If you develop your software in groups, create a framework, or just want to show your latest development project to other people, your want documentation for your code. For Objective-C in Xcode projects there are solutions like HeaderDoc or AutoDoc, but the lack of solid documentation seems almost ironic. So I found doxygen, which has better documentation and supports multiple platforms, multiple programming languages, and multiple output formats.
Read the very helpful post at http://www.geek-nation.de/2012/12/doxygen-in-xcode-4/