Placing 2D images in 3D space with ARKit + SpriteKit

For my AR Copy & Paste app, I need to be able to place 2D images in the real world. I’ve never used ARKit before, so this will be an adventure. I also want the images to billboard, so that when the user is looking at them, they are facing the user, not turned around.

The reference page that is most helpful to me:

It turns out that this is a common example app for SpriteKit, so I set up the example ARKit app and played with that. Every time you tap the screen, it places a new sprite. I tried it with text as well, and placing other images.