advertises such a system. But from the make-up of the site and no geo-science related work that they link to (at least what I could find) I assume it is just an advertisement for the internet of things (IoT) and economic interests outweigh a scientific usefulness.
But opinion aside, does a denser (home made) sensor network than the status quo of earthquake watchers in the hot spots and ODAS buoys really shorten warning times? Hasn't this been worked on in the wake of the 2004 Indian Ocean tsunami?
It would be interesting to know if home made sensors and IoT really could contribute to shorten warning times from official sensor networks.