At my Outdoor First Aid training, the trainer spent time showing everyone how to get What3Words app to display 8-figure OS Grid Refs. I really wish the OS app was just slightly better at showing your location.
Everyone on the course loves W3W. The trainer did go through in detail why OS was better than W3W for mountain rescue, which was great, and he expressed frustration that the ambulance service will only accept postcodes and W3W.
Can't wait for #What3Words to go bust 😬