The trick is to develop an iOS ARKit application, and once that is working, convert it to a Swift playgroundbook.

The benefit of doing this is you can use the full power of Xcode:

• Use Xcode's editor to write your app.
• Use Xcode's specialized views to manage your Scenekit art assets.
• Use Xcode's debugger to debug your app.

• You can't use Interface builder (no storyboards or nibs).

1. Open terminal
2. cd to the "arkit2" directory.
3. run makePlayground.sh

This will create an "arkit.playgroundbook" in the ".." directory.

1. Open Finder
2. Open a Finder window and choose "Airplay" from the favorites menu.
3. Turn on your iOS device.
4. In a second or so it should appear in the "Airplay" Finder window.
5. Locate your arkit.playgroundbook
6. Drag-and-drop arkit.playgroundbook onto your iOS Device icon in the Airplay Finder window.
7. This should transfer the playground book and automatically launch the Playground app on the iOS Device.