First we need to add the background file to our project. Xcode 5 offers new ways to handle your assets. Find
background.png in resource files for this chapter. Find
images.xcassets in the project navigator on the left-hand side of the screen. Click on it and you will see a list of resources currently in your application. Drag-and-drop
background.png into the left-hand list near Appicon and LaunchImage. Background will be added to the list of available resources. Select it and drag it from the 1x box to the 2x box, as this is a high-resolution image to use on retina devices.
Next, we should utilize this image somehow. The first thing that comes to mind is to make
SKSpriteNode out of the image and move it in ...