This blog post was written by Giang Vo, iOS developer. Contact him though email.
Part 1: basics on naming classes, variables, accessors, general methods and abbreviations.
Apple has laid out a set of guidelines as to how code should be written for maximum clarity and integration with the frameworks. In addition, there are some undocumented conventions that Cocoa developers often use.
In essence, the human factor present in Apple's products for the end user can be found in Objective-C and Cocoa themselves.