Testers say the QuakeAlert App gave them a 12 seconds heads-up before a quake on Tuesday in Southern California.
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The app can tell the expected arrival time of the earthquake, distance from the epicenter and the expected intensity.
It uses real-time data from nearly 900 USGS sensors placed along several West Coast fault lines. And sends early warning alerts to users' cellphones.
"The one that people are obviously concerned about is the big one," said the app's founder Josh Bashioum. "And that scenario is actually loaded into here, where we have the San Andreas basically unzip from the Salton Sea and in LA. If we run that, you can see we'd get roughly about 50 seconds warning in that scenario."
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The alert also gives emergency crews a jump on the shaking.
Right now, the app is still in a Beta Testing phase, with a goal of releasing publicly next year. Get a closer look at the app here.
Get the latest stories and videos on recent earthquakes in the Bay Area and around the world here.
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