Historypin is a great website that allows you to place old images of places on current Google Streetview imagery. This past July they introduced some nice new features including a free Android App.
TheÂ Historypin Android AppÂ allows you to view historical imagery layered over the current map for where you are standing (provided imagery is available). You can also use the app to add imagery to the map. The app gives you access to stories about the imagery you’re viewing on your phone or tablet. This could be great app for students to use when they’re on a walking tour of city with a rich history.
You can learn more about Historypin in the video below.