joined by kym mcnicholas, and ben parr, the world's best public service announcement demonstrates what this thing is. the first time you showed it to me, i just got it. you have smartphones in everybody's pocket, somebody's 100 yards away that knows cpr. that's kind of how that started. >> it did. it started at lunch i was with my it staff on a regular day, heard the sire ren and wondered where the crew was heading and pulled up in front of the deli we were eating at. we were aware of someone in great need on the other side of the wall. i had a paramedic with me, defibrillator in my car, on duty, crowded restaurant, shocked something could occur so close to us without us being aware of it. that was the genesis of the app. we worked the rest of the afternoon on napkins an got a plan together. >> how does this app actually work? uses location-based technology, correct? >> it does. users download the application, they opt in, saying, i'm cpr trained, willing to help in time of an emergency. if an emergency occurs we determine to be somebody who's unconscious and unresponsive, we'll dispat