The New York Times reported that "Frequently, location data
companies make packages of code that collect phones'
whereabouts. Developers who add this code to their apps can get
paid for location-targeted ads, or earn money for providing the
location data, or get free mapping or other services for their
apps." The December 10, 2018 article entitled "How The Times Analyzed Location Tracking
Companies" included these comments:
Reporters tested both the Android and iOS versions of 10
apps: nine that had been flagged by academics researching Android
devices or by people in the mobile location industry, as well as
The Times's own app.
The Times analyzed the location transmissions from each app
by looking for the latitude and longitude where testing was
conducted, as well as known Wi-Fi IDs, which can be used to
triangulate location. Reporters tallied only the transmissions
precise enough to place the device in the correct
building.