What do they mean by screen space text in ARKit?

When I went through the video for session 805, Creating Great AR Experiences, and they mention using screen space text when displaying text in AR. They use the example of their Measure app that works quite well.

Is this something that is already in ARKit 2 or does we have to roll our own? I know that when using SpriteKit the objects are always facing the user but there doesn’t seem to be any way of doing this with SceneKit based AR.

It would be fantastic if Apple put Measure up as sample code, but short of that does anyone have any ideas where I should start looking? I’m thinking there is a boatload of geometry in my future that may or may not be fast enough to maintain 60fps to keep updating the Euler angles of the labels based on the camera position.

@paradox927 Can you please help with this when you get a chance? Thank you - much appreciated! :]