Webapp / Native app in 3D space (VR/AR)

First some background information on what I am trying to do:

I have an existing app. It can work as either a web app, or a full-fledged Android app (written using web technology and Cordova/PhoneGap). What I want, is to put my existing app in 3D space and have it stick to a certain position, relative to your heads rotation. In other words, when you put on your AR glasses, you will see a screen right in front of you, hovering in the air. When you look away, the screen stays put.

I have solved the screen position problem by using the gyro to move the Unity camera around. That part seems OK for now (although a bit "shaky").

What I am stuck on is getting the actual app into my 3D space. I just figured a web view would be trivial, but it seems like this is not the case. The only platform where this is kind of solved it appears is on desktop. On Android there seems to be no good options.

Is this a problem that is solvable? How can I do this?

 

For future reference, I kind of found a solution here:
https://jerome.gangneux.net/projects/2017-02-android-vr-webview/

It seems to actually work, but it also has some limitations (which is to be expected I suppose).