List of tools that developer can use when working with Sprite Kit:
Sprite Sheet generation tool with option to export to your favourite game framework (cocos2d, Sprite Kit (soon), Corona, …)
Great tool for generating and painting normal maps for 2d game objects and art
Collision shape generator with option to export to your favourite game framework (cocos2d, Sprite Kit (soon), Corona, …)
Fantastic bitmap font editor tool
Fantastic tool for rapid prototyping and development of cross-platform 2d games
Great Particle effects editor
SKPhysicsBody Path Generator
Nice online tool for generating polygon path for your image to be used with SKPhysicsBody
Great set of tools including sprite sheet editor, collysion shape generator, and animation editor
Sprite Kit Designer
A powerful integrated tool to create Scenes with Sprite Kit. It contains a wysiwyg Layout Editor to create complex node trees and edit all the properties of the nodes, a keyframe based Timeline Editor to create actions and a Resource Manager to manage Textures and Texture Atlases..
Sprite Kit Physics Debugger
Great open source debugging tool allowing you to draw and see the real physicsBody.
Provides with details (all properties) of Sprite Kit classes in the debugger. Requires Xcode 5.1.
TilemapKit is the first complete hexagonal, staggered & regular isometric and orthogonal TMX tilemap framework for Sprite Kit
Another nice sprite sheet editor