Countries of the past, rulers and kings, battles, famous people of the era - all after you pick a place on a map, set a year on a time slider. Explore over 500k maps down to streets, 3D & Augmented Reality. The "Google Maps of History" in your pocket.
I like the feature of being able to move the timeline of the map to see the rulers and borders and battles as well as being able to see how the maps looked in the past.