"We require location to use the app only to extent to know what your location to make sure something critical is happening near you," said Praveen Arichandran, Head of Growth Citizen.
It's called "Citizen."
It's completely free for you to download.
The app works with the 911 system to alert you of any emergency, based on your GPS location.
It also allows you to interact, to give updates on what's happening in real-time.
Emergency responders can also use the information to help formulate a plan of attack.
It's only available in the city of Philadelphia right now, but Citizen plans to expand coverage in the near future.