After offering a preview of AR Stickers back in October, Google is ready to start pushing out the feature to Pixel ($100 at Amazon) owners starting on Monday. With the AR Stickers, users can place random digital objects and text in a photo or video, capture it and share it (with just a few taps). Right now the number of packs is a bit limited, but Google will probably build on on the service.
Open the Play Store and visit the Updates section. There should be updates available for two apps: ARCore and AR Stickers. If not, you can try visiting the respective app pages directly (ARCore | AR Stickers).
If you still don't see updates available, keep checking back. The feature is slowly rolling out.
Where's the app?
After you've updated AR Stickers and AR Core, open the Camera app on your Pixel phone, slide out the menu from the left-hand side of the screen and tap on the new AR Stickers option.
Each time you activate AR Stickers, move your phone in a circular motion as demonstrated on the screen. Doing so allows your phone to scan and map the area.
With scanning done, use the menu at the top of the screen to select and drag a sticker onto your screen. Pinch on the object to shrink or enlarge it, or use two fingers to raise an object and make it hover off the floor.
With an AR Sticker added to a scene, walk around and view it from different angles. Each sticker in the Star Wars and Stranger Things packs has its own set of phrases and movements. View each sticker for a few seconds to get a feel for what it does.
You can use the same sticker more than once in a given shot. For example, at one point I had five Stormtroopers surrounding BB-8.
At any time you can move a sticker to a different position by dragging it with your finger, or if you'd rather start over, tap on the trash can to clear all stickers.
When a sticker is being used, the Camera app will display the option to record video or capture a photo. Whatever route you go, it's saved to the Photos app just as any other photo or video is. From there, edit or share it as you see fit.