Google (and Apple) has been partnering with ShakeAlert from USGS for quake reporting on west coast of US. But that takes network of seismometers and detection system.
I could see smartphone seismometers being useful for areas that don't have all that. OTOH, if phones are useful seismometers, it should be possible to make cheap, dedicated ones.
The closest one (that I know of) is approximately 1000 km away, and it does provide data about earthquakes, but only after the fact. They already have some information sharing, because I usually look up the info on usgs.gov, but almost certainly not in real time.
