Mopedi is an offline wikipedia reader. You can download multiple ready made wikipedia databases directly from within the application. The databases have full article text and include images and equations.
In addition to Wikipedia, Mopedi has integrated mapping capability when in online mode. Using that and wikipedia location information you can find distances between different places, show places on maps and create routes. These can be bookmarked for offline usage and further editing.
Mopedi is useful when travelling, sailing, caravaning, ... always when there is no internet available. It is also handy when you want the reference cabability of wikipedia without the distractions of internet.
Check http://mpaja.com/mopedi/db for available databases.
Part of the proceedings are donated to Wikimedia Foundation.