SUDBURY -- Several police services across Ontario are using a new mobile app that helps first responders find 911 callers who don't know their location.

It's called What3words and it can find a person in distress even when there is no cellphone service.

Greater Sudbury Police Service are using the app in its communication centre, which can locate a person with a high level of precision -- within 65 metres.

"So the What3words app turns all the world's geography into 10-foot squares and then assigns three words to each one of those squares," said Kaitlyn Dunn of the Greater Sudbury Police Service.

"What3Words actually runs off a satellite instead of cellular service. So the satellite is what generates the three words based on your location services, which you turn on through your phone services."

Critical tool

The Ontario Provincial Police is also using the app. They said it's a critical tool when people out hiking, hunting, boating or on outdoor adventures find themselves in an emergency, but don't know where they are.

"This app will help police in locating persons that are in remote areas, forested areas where (their cell) signal is very limited, on vast waterways without any cell service," said OPP Const. Michelle Coulombe.

Police are asking people to download the free app before finding themselves in an emergency.

"There may be a single address assigned to a very large location, or an individual may not know where they are lost or stranded and they can't see a landmark or any kind of address information to provide to our communications centre," said Dunn.

Police want people to know the app can save lives. It helps them deploy the proper resources such as boats, ATVs or even the search and rescue helicopter from CFB Trenton.