What’s Shaking NZ? is an earthquake notification/monitoring application built here in New Zealand by Adam Speakman. It uses the free Geonet data feeds to get the latest quakes, right on your Android or Windows Phone.
It is completely free to download on both platforms - it doesn’t even have ads. It is also open-source, meaning you can look at (and contribute to!) the code that runs the application. The source code can be found on Github for both Android (Coming Soon!) and Windows Phone.