The most common use of NSBundle seems to be to keeb nib files and such files. But from what I read it seems I could bundle classes as well but I can't find any example of how to achieve this. Could you provide an example of this and if so, can you tell me if dynamically loading the methods of such class into an existing class would be forbiden by Apple?
It is indeed forbidden to dynamically load framework bundles in iOS. See below link for relevant docs:
Note: The creation and use of loadable bundles is not supported in iOS.