This link is intended to make using the Mac OSX and iOS Keychains as easy as NSUserDefaults.
It is a KVO-compliant Cocoa wrapper around the Mac OSX and iOS Keychains, and the model for this wrapper is NSUserDefaults, so the intent is that for the common cases you would normally want to call:
[NSUserDefaultsController sharedUserDefaultsController]
You should be able to call
[PDKeychainBindingsController sharedKeychainBindingsController]
And for the common cases you normally would have called:
[NSUserDefaults standardUserDefaults]
You should be able to call
[PDKeychainBindings sharedKeychainBindings]
There are a couple of differences between the implementations. First, this class is only valid for strings, because that's what the Keychain accepts, so the methods that take non-string objects (like arrays and dictionaries and the like) have been omitted from the class. Secondly, right now, only "immediate mode" is implemented, so you can't set a bunch of values and then call "save" to do only one write, and there's no "revert to saved values" functionality).