If the earth shakes, this app will let you know. Quakefeed notifies you of any earthquake of magnitude-6 or above around the world and brings you data on recent quakes from the U.S. Geological Survey. You can filter the quake list by magnitude, starting at 2.5 or higher. Quakefeed’s sharp map feature (complete with fault lines) makes it simple to visualize a temblor's location. Last but not least, a curated news feed provides a one-stop shop for earthquake news.
Being notified of every magnitude-6 or above quake around the world may be a boon for some users and an irritant for others (according to the USGS, there are about 134 quakes of this size each year). A $1.99 upgrade lets you customize quake notifications, alerting you to, say, only magnitude-4.0 and larger quakes in New Zealand.