I live in an active earthquake zone and some of my family members do as well. The Epicenter app makes it really fun and easy to see what kind of activity is going on around us, at which magnitude and what frequency. I love the slick twirling globe and intuitive features. You can auto play the earthquake activity timeline from start to finish, or move the slider back and forth manually to study certain dates.
They also give you two different view toggles: you can choose to see all earthquake occurrences accumulate on the screen, or see them appear and disappear as the timeline progresses. The accumulation view really helps you get a quick visual sense of how much activity has been going on in an area of interest. The interval view makes it easy to see all the places that had occurrences on any given date. You can tap on each dot to see exactly where and when the earthquake occurred.
This app really gave me and my family a new understanding of just how much earthquake activity is going on all over the world...especially where we live! A fun little tool to get friends and kids interested in seismology (and bonus by-product: staying sharp on geography!)
Lastly, Epicenter has a widget you can include in your Today view in the iOS Notification pulldown. It tells you the most recent occurrence closest to you as well as the latest largest one in the world. I love to see interesting tidbits like that in my Today view.
MStaySweet about Epicenter - Global Earthquakes