"the proprietary data is not accessible outside their apps"
This is not true. Many APIs are available, specifically to allow building 3rd-party apps: Directions API, Distance Matrix API, Elevation API, Geocoding API, and so on. See https://developers.google.com/maps/pricing-and-plans/
This is not true. Many APIs are available, specifically to allow building 3rd-party apps: Directions API, Distance Matrix API, Elevation API, Geocoding API, and so on. See https://developers.google.com/maps/pricing-and-plans/