That app with Google Cardboard allows you to try face recognition with Virtual Reality elements. Take your phone, plug it in your Cardboard and look around - simple! It is super cool for you and super awkward for others!

Download from Google Play is here: https://play.google.com/store/apps/details?id=pl.tajchert.faceboard

It is a one night project, build for fun on a sample of OpenCV with use of modified library (to support stereo vision, and red tint) just to see if and how face recognition can be done with Cardboard.