This app was mentioned in 3 comments, with an average of 1.67 upvotes
which app or service is sending alert/warning? I had 'Hazards' with all the alerts on but received nothing (it should have sent an alert for an earthquake > 4.5 and for the tsunami warning later) https://play.google.com/store/apps/details?id=com.cube.gdpc.nzl.hzd
The Red Cross app or if you are in New Zealand their Hazards app.
https://play.google.com/store/apps/details?id=com.cube.gdpc.nzl.hzd
A bit shit too though.