The Getting Started guide says to download sprite builder from the Mac App Store:
"Currently, the way to install Cocos2D-ObjC, is to download the editor SpriteBuilder from the Mac Store. After installing SpriteBuilder, you can simply create a new project, and either continue in SpriteBuilder, or switch exclusively to Xcode."
The link takes you here:
However, you get a dialog that says it isn't available in the US Store? So how do I get it?