Built in Sprite Kit level designer in Xcode 6
ios8, sprite-kit, xcode6
Solution
I've found it. Just create a new project with the 'Game' template. This template creates automatically an sks (Sprite Kit Scene) file. In the scene you can drag your sprites, define bounding boxes, physics, ...
Update: Ray Wenderlich has created an excellent tutorial
Problem
I found this hint in the Xcode 6 beta documentation: 'Support for Sprite Kit has been significantly enhanced with a new Sprite Kit level designer, ...' Does anybody know, where I can find it? Thanks, Stefan