I know that not everyone celebrates Christmas, but for those that do or for those that just love Christmas I did an Android application to make this Christmas devtastic!
Why not start and build something using your skills? There are lots and lots of programming languages so why to stick to a single one?
ArCore for Android. I started with the Sceneform sample found here.
Going through the sample you will learn how to display an arSceneView and how do you detect a plane in order to place different virtual objects.
The next step is to add a bunch of models from poly. Notice that those are published under a CC-BY license. You're free to use them as long as you credit the author.
Android devices with Android version > 7.0
Go ahead and post your Christmas tree! 🎄🎄🎄