By jove, it works!

California's earthquake early warning app, MyShake, sent out its first alert Tuesday notifying people nearby of a swiftly incoming 'quake.

At around 10:30 a.m. local time, a magnitude 4.3 earthquake in the central coast-adjacent town of Cholame prompted the app to send warnings to over 40 people nearby who would be impacted by the shaking, according to the Los Angeles Times.

The idea of the app is that giving people even secondsof warning allows time to drop, cover, and hold on before the shaking starts. In the case of the Cholame quake, notifications were sent out to those affected people just 8.7 seconds before the earthquake hit.

MyShake, which launched in October, is connected to sensors placed along California fault lines that detect the beginnings of earthquakes. Throughout California, if sensors register a magnitude 4.5 earthquake or above, the app will send out alerts to people in the affected area.

Though the Cholame earthquake was only a 4.3, sensors originally registered the earthquake as a 4.8.

MyShake also allows its users to report their experience of earthquakes. The app shows that 151 people reported their experiences — but only 15 felt "light" shaking. The remaining 132 felt zilch.

An underwhelming debut? Sure. But that's definitely a good thing.