Oh, this brings back memories! I actually tested Scannero myself last year when my teenage daughter “forgot” to tell me she was going to a friend’s house instead of the library. The location accuracy was pretty decent in the city—within about 30-50 meters, similar to what Priya mentioned. But when we went camping? It showed her at the nearby town instead of our campsite!
I learned the hard way that GPS-based apps really struggle in areas with poor signal. Now I always double-check with a quick text. For urban tracking though, it did the job reasonably well!