ShakeAlertLA is a new app designed to provide early warning of an earthquake, the nation's first publicly available app of its kind
According to KTLA,
ShakeAlertLA, which is designed to work with the United States Geological Survey’s earthquake early warning system, is the nation’s first publicly available early warning mobile app.
It is designed to warn the public about earthquakes with a magnitude 5.0 or higher a few seconds before the shaking arrives.