@BradRubenstein @briankrebs The name used for it in location circles is WPS https://en.m.wikipedia.org/wiki/Wi-Fi_positioning_system
There are a bunch of open APIs that allow navigation. I think Google had a semi public API at some point until a country took the@ to court for unlawful packet capture.
For phone makers it allows them to provide location services with a super low power budget. (GPS eats battery and you’re normally scanning for WiFi anyway)