We build indoor navigation systems for hospitals in Canada and it is indeed a huge problem. The larger institutions are like a maze with wings and additions added over the course of decades. Making a route to your appointment though 3 buildings, up 2 elevators, and over a wing is easy. Helping you actually stay on the route as you follow it is not. If this new tech is cheaper to deploy than dozens, if not hundreds, of wifi beacons then it could be a real win.