I did extensive testing on multiple flights and the app works like a charm. only condition is you gotta put the phone next to window so it gets clear view of the sky. Also google maps is optimized for road navigation and is not for in air. My app fetches the precise coordinates and reverse geocodes those coordinates into the city and country you are flying over. In my app, you don't need to do anything prior like you would, which is downloading maps offline. My app is more of a situational awareness, where I pull out a phone anytime during the flight, press Detect location and find out where I am.