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...

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