DroidPlane is a mind mapping application for Android. It allows you to open FreePlane  and FreeMind  documents on your Android device. DroidPlane is optimized for large mind maps with many thousand nodes. The map is not displayed in the conventional format, but as a navigable tree. This makes it possible to browse through large mind maps on relatively small screens.
Files can be opened directly from Dropbox or any other file manager. At the moment, it is only possible to open files read only. Editing mind maps is not yet possible.
The application is in a very early state right now. Please send me an email to email@example.com if you have wishes, suggestions and feedback. Thanks!
 FreePlane: http://freeplane.sourceforge.net/wiki/index.php/Main_Page
 FreeMind: http://freemind.sourceforge.net/wiki/index.php/Main_Page