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

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

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

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

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