The service interacts with client software on a mobile device to sense presence of wifi networks and determine the device's physical location within Japan based on that access. The local client retrieves listings of wifi networks currently available to the device and submits the information to the server, which returns a location suggested by that combination of network access. The service maintains a database of locations and wifi access profiles which users can update to increase its accuracy over time.
API methods log device characteristics and wifi access as reported by the installed client and return matching location, with estimated accuracy within 5-100 feet, depending on the density of wifi access points and other variables. Methods also allow device reports to update the database of locations and wifi access points available there.