Google ARCore and AR Stickers go live for Pixel 2 phones and OG Pixels running Android 8.1
Unfortunately, the image quality when using AR Stickers is visibly decreased and you can't tap to focus, meaning that close-ups are off the table right now. Google is likely doing this to ensure good all-around performance at launch. Otherwise, you can change the size of the 3D characters by pinching with your fingers, move them up and down by swiping with two fingers, and rotate them by spinning clockwise or counterclockwise with two fingers. You can also drop multiple characters on-screen and watch them goof together.
A nice touch from Google, albeit nothing groundbreaking, is the fact AR objects react to environmental lighting changes environmental light in real time. For example, if your scene is darker, the 3D character won't be appear unnaturally bright (as has been the case with Snapchat filters, for example), but will be adjusted to fit in with, more or less.
If you want to try out the new AR Stickers, you need a Pixel 2 or an OG Pixel running Android 8.1. Just visit the Play Store links below to update the ARCore framework and download the AR Stickers app.
Things that are NOT allowed: