Père Lachaise:

Le Pere Lachaise is a beautifully-rendered, interactive map of one of the world's most famous cemeteries. This is not only the resting place of many of the world's beloved personalities, but it is the largest park in Paris. Take time to walk its graceful streets while studying centuries of fascinating grave art. In addition to the clearly marked avenues and plot numbers, this map includes a list of some of the most well-known inhabitants. Search the list and tap on a name to see the location of their grave marked on the map. Then, tap on the marker to find out who they were!

In addition, you can search for bathrooms (now there is a useful app!), and for the water fountains that allow visitors to water the flowers and plants they have brought.

Direct links to information on the internet for almost everyone in the search list will soon be available so you can research the graves' owners directly from your spot in front of their tomb (internet connection required).