There are a bunch who basically pay apps to use their api and then take the data.
Apple was right to kill that imho. IIRC that was foursquare's pivot
There is also lot/lon in programmatic bid requests, but I don't think they're super accurate or granular and lots of fraud. (could be wrong, just from my small experience buy side using DSPs seeing lots of lat/lons being smack in the middle of a city)