A new free app could save your life by connecting citizens who are trained in CPR with patients who are suffering from a heart attack. The app, called PulsePoint, is being used in 2,000 U.S. cities in 28 states, and it helps people trained in CPR if somebody nearby needs their help.

It saved the life of 60-year-old Seattle resident Steve DeMont, who was biking from his neighborhood to his job in Bellevue, according to various media reports. When he arrived at a bus stop near UW Medicine, he noticed he was having a problem.

“I stopped the bike, I got off and I immediately felt lightheaded,” says DeMont according to a MYNorthwest.com report. “Next thing I know, I’m in the ICU.”

DeMont had suffered from a heart attack, and an alert citizen who had the PulsePoint app used it to summon people in the immediate vicinity to the location who could perform life-saving CPR on him.

The app was invented by Richard Price, who spent 33 years as a fire chief in California. He got the idea after hearing sirens while having lunch and seeing paramedics pull up to the building as someone had gone into cardiac arrest. Price knew how to use CPR and could have helped had he known.

So he invented PulsePoint.

“When somebody calls 911 and reports somebody who’s unconscious, and the dispatcher determines that that’s likely a cardiac arrest, they dispatch resources,” Price said according to the report. “But our software that’s running in the dispatch center looks to see if we have anybody who is trained in CPR in the immediate vicinity. We notify them and provide them a map so they can see where the patient is located. We also show any nearby access to public defibrillators, AEDs, so they can either start CPR or use that AED while the professional responders are on their way to the scene.”