In iOS 8, you can set the scene’s SKView to allow transparency and set the scene’s background color to have transparency. Then views behind the SKView will be seen.
UIView *parentView = ...;
[parentView addSubview:backgroundView];
[parentView addSubview:skViewWithScene];
skViewWithScene.allowsTransparency = YES;
scene.backgroundColor = [UIColor clearColor];
[skViewWithScene presentScene:scene];