A set of object oriented frameworks that provides a runtime environment for apps running in Mac OS X and iOS.

Part of the AudioToolBox framework. Plays notifications for UI events (button clicks). Designed to play sounds that are 30 seconds or shorter.

It is responsible for providing the graphics and sound APIs that you will use to build your games. Includes Core Graphics - Core Animation and Core Audio.

Deeper then AV Foundation. You can precisely synchronize audio playback with your application.

Adds social functions to your game - Leader Boards - Achievements - Friends Lists - Turn-based Gaming - Auto matching to anonymous players

Lets you set up a game that your players can play over a period of time.

The most basic components of the iOS operating system including the Kernel - file system - networking components and device drivers.

Simple - Easy to learn - Short levels that can be played in minutes - Simple control schemes - Interact directly with the game actors.