The Concussion Recognition and Response app was co-authored by Canadian Jason Mihalik of the Matthew Gfeller Sport Related Traumatic Brain Injury Research Center at the University of North Carolina at Chapel Hill.
Mihalik, who specializes in sports-related head trauma, says the diagnostic app helps users check for signs of a possible concussion after an athlete has been seriously hit.
If the answers point to a possible concussion, the app shows a 911 button so users can call for medical help right away, he added.
"Is their condition deteriorating? Is there clear fluids coming from the ears and the nose? There's a whole list of clinical red flags and there's a 911 button on that screen," he told CBC News on Tuesday.
The app asks users to look for symptoms that include vomiting and balance problems. They are also prompted to ask affected players if they have a headache, for example.
Mihalik said the app is better than coaches asking players if they are OK before sending them back into the game.
"It actually forces the coach to pay attention to the kid," he said.
The app is available for download at Apple's App Store for iOS devices and the Google Play store for Android devices. It costs just under $4.