Versatile, yet easy to use. Use Marble similar to a desktop globe; pan around and measure distances. At closer scale it becomes a world atlas, while OpenStreetMap takes you to street level. Search for places of interest, view Wikipedia articles, create routes by drag and drop and so much more.
We are working on an Android app that features beautiful OpenStreetMap vector maps and an easy-to-use interface. Join us and help getting it ready for the first release!
At its heart, a software library powers the Marble applications -- also integrated in a wide variety of other projects like Digikam or the KDE workspaces. Using the Marble library in your project requires only C++, Qt and adherence to the LGPL 2.1. Last but not least you can extend Marble itself using plugins.