SpriteKit
SpriteKit provides a graphics rendering and animation infrastructure that you can use to animate arbitrary textured images, or sprites. SpriteKit uses a traditional rendering loop where the contents of each frame are processed before the frame is rendered. While your game determines the contents of the scene and how those contents change in each frame, SpriteKit does the work to render frames of animation efficiently using the graphics hardware. SpriteKit is optimized so that the positions of sprites can be changed arbitrarily in each frame of animation.