Project Files

app delegate

The starting point for the application – the app must have one.
Manages a single top level UIWindow.


Called right before the app is ready for the user – your chance to prepare the application for action before the user can do anything.

xib doc window

File's Owner

An instance of UIApplication – manages the event queue for your application

First responder

Can be ignored for iOS


Subclass of NSObject created by Xcode for this project – this is where you edit the source code for this class.


An instance of UIWindow which represents the applications only window.

Interface Builder Windows Used To Design

Library and Inspector needed all the time.


View Objects

Visible to the user.

Model Objects

Hold data and know nothing about the UI.

Controller Objects

Keep the view and model objects in sync, control application flow and save model objects out to the filesystem.  The default for a new application is 'AppDelegate'.