SpriteKit and the 3D game framework, SceneKit, were not the first methods used for developing games in iOS. We'll quickly see why it became a welcomed addition to the developer toolset. Initially, we, the game developers, had to practically talk directly with the GPU using the OpenGL API to put both 2D and 3D graphics/vertices on to the screen. On the upper level, there always was Foundation and CocoaTouch to interact with user gestures to manipulate UIKit objects, but dealing with game development essentials, such as SpriteSheets, mipmaps, normal maps, partial emitters, bounding boxes, and culling, involved some level of lower-level structuring. Apple made those calls to various graphics buffers and VBOs slightly easier when they created their GLKit framework in 2011. Thankfully, various third-party frameworks, such as Cocos2D, Box2D, Sparrow, GameMaker, Unity, Unreal Engine, and others made this process less engineering-intensive in an effort...