The Earthquake Network initiative aims at developing a smartphone-based crowsourced early warning system able to detect earthquakes in real time and to alert the population. Smartphones (or tablets) are able to detect earthquakes thanks to the accelerometer on-board each smartphone.
When an earthquake is detected, users with the application installed are immediatly notified. As the waves of the earthquake travel at a given speed (from 5 to 10 km/s), it is possible to alert the population not yet reached by the damaging waves of the earthquake.
Note that the system is currently at the experimental stage. Detection of earthquakes is influenced by the number of active devices in the area hit by the earthquakes, by the their spatial distribution and by the sensitivity of the accelerometers.
The application also shows information on the earthquakes detected by the national and international seismic networks. Information on a given earthquake is usually published with a delay ranging from few minutes to many hours, depending on the network.