SIOUX FALLS, S.D. (AP) — Sioux Falls is launching a free smartphone app that notifies users when an emergency happens in a public place.

Fire Rescue Division Chief Jeff Helm tells the Argus Leader (http://argusne.ws/UThEnK ) that the PulsePoint app uses GPS to notify users within walking distance. The goal is to get a person on scene faster than emergency responders.

The app is designed for both Android and iPhone devices.

When a 911 call is dispatched, the message is sent simultaneously to EMS responders and PulsePoint, which will notify users within a half-mile of the scene. The app shows the user's location, the location of the emergency and the location of the nearest Public Access Defibrillator.

Helm says a nearby person could get CPR started more quickly if they're in a nearby store aisle.