I'm curious if anyone knows of any downloadable Objective C sample code for the gang of four design patterns out there? I am looking for working sample XCode projects and don't mind paying!
Incidentally, if you're looking for other languages, you could start here for Java or here for various languages
It's no Gang of Four but Apress has Pro Objective-C Design Patterns for iOS by Carlo Chung which has many of these patterns in it. Other than that, I'm not sure of one place that has so many of these patterns represented in Objective C.