One of my daughters uses it, even though her car has built in sat nav. She swears by it and she’s a police officer! It shows you speed cameras (which my built in sat nav also does) but users input info about hazards or things to look out for on their routes, so as to warn other users.
She gave me a lift home from hospital the other day so I was able to see it in action. When we were on the motorway it warned us of a stationary car in the hard shoulder and as we passed it a box popped up to ask if the hazard was still there (yes or no). I tapped on yes (as it was) but presumably if I’d clicked ‘no’ the warning would have been cancelled for other users.
It’s not perfect as it depends on the accuracy of user input. For example, twice it warned us on Police on the motorway, but it was actually traffic officers (civilian) who deal with breakdowns etc and have no powers to measure speed, issue tickets etc. This is a common confusion with many road users who don’t know the difference (if you don’t, Police are yellow and blue check, traffic officers yellow and dark grey check – looks black).
My daughter says that it’s worth altering the settings to simplify the displays and only focus on critical info. For example, the default setting shows you the location of other Waze users, which is of no use and just distracting.