Yes, that's what I meant when I said SpriteKit contains an engine similar to Box 2D. I thought my comment was reasonably clear about SpriteKit not just being the physics engine.
According to my tests it is not Box 2D, it produces significantly different results and only implements a subset of functionality. I've been told by others with more experience that it isn't Box 2D also, but if you have more information I'd like to know for sure.
Thanks for that, that's really interesting. It behaved differently in my experiments so I assumed it wasn't the same — but it must just be a different configuration.
According to my tests it is not Box 2D, it produces significantly different results and only implements a subset of functionality. I've been told by others with more experience that it isn't Box 2D also, but if you have more information I'd like to know for sure.