How to get started AR Developer

I am always keen to try new technology powered by Unreal Engine 4 and love to develop on those.
I did develop for VR , mobile and PC.
Now I would to develop on its counterpart ie AR.

But the only plugin I did found was for iOS.

Is there a way to develop for AR for windows using a free plugin or any sort of guide on how to proceed in AR Development using UE4.

Thank You.