The What Three Words app is very popular here in the UK. I started using it about twelve months ago as a Detecting Club I dig with use it for directions to our digs.Have a look at the 3 word app emergency fella show me this every 3 x3 meter block in the world has been allocated 3 letters so trying to give them heep of numbers 3 words how easy
90% of the time it works fine, but there is one area we visit and it just goes haywire...
I have no idea if it's the App itself, or whether it's Google Maps that it interfaces with, but you can be driving around and it will say "1km to destination" and then a minute or two later it will be "2.5km to destination"...I end up having to reset the app and do the search again until I get the proper route for the final leg of the trip.
I have only come across the issue in one specific geographic area so put it down to a glitch in the matrix so to speak, but it doesn't fill me with confidence..
Personally I still prefer using 6 or 8 figure national grid references to denote a location...
I have a different app on my phone that generates them so I can record Find spots ect for my records...I don't need network coverage for it to work either, which is a bonus.
Failing that, I also have a Garmin 62S from my hiking and deer stalking days, but rarely use it as Grid Ref App on the phone does everything I need....