Fire-tracking app Watch Duty has become an important source of information for Los Angeles residents threatened by ongoing wildfires.

as TechCrunch’s Maxwell Zeff explainsthe app relies on a network of active and retired firefighters, first responders, official government reports, and volunteer reporters monitoring radio scanners to offer real-time updates on active wildfires .

During this week’s fires, where official alerts were either buggy or inaccurate, Watch Duty rose to the top of Apple’s App Store charts. And on an interview on Saturday with The New York TimesCEO John Mills said the app has been downloaded 2 million times since Tuesday and has seen 14 million unique users this week.

Mills said the app is run by a nonprofit funded primarily by donations, with 15 full-time employees and 200 employees. He insists that Watch Duty collects very little personal data about users and that he has no intention of selling it.

“I owe it to my community not to be a disaster capitalist,” he said.