As I started to work with Xcode I started to get utility routines that I would like to use across multiple projects. The first 'solution' is to just copy those into the new application. From a software engineering standpoint this is not bad, it is very bad.
I found a VERY useful post at
This provides in great detail how to establish a static library which can then be linked into your applications. Any routine that will be used in more than one application should be in a static library.