Google uses a combination of GPS and nearby wifi signals to figure out where you are, and it is astonishingly effective. I enabled location history for a day an

Google uses a combination of GPS and nearby wifi signals to figure out where you are, and it is astonishingly effective. I enabled location history for a day and could see data points for different rooms in my apartment. If any random app can access that data, I wonder why they don't integrate it with the E911 feature that's already built into android.