For $20, Build a VR Headset For Your Smartphone

An anonymous reader writes "Not everyone can drop a few hundred dollars on a VR headset, but that doesn't mean they can't experience VR! For those with the time and a bit of handiwork skill, this DIY guide from guest writer Ohaple will show you how to make a smartphone-based VR headset for as little as $20. Along the way, you'll learn the hardware and software basics of a VR headset." This project screams for a ready-made commercial version; does anyone know of existing purpose-built headgear? As one of the comments on the linked tutorial says, Poppy seems close, but lacks an LED for tracking.