With Samsungs recent drive to increase screen size to enormous levels :-) a lot of OSM Android apps have run out of screen real estate that they can reasonably use. Luckily it is trivial to add support for Samsungs multi window facility (IMHO currently available on the Galaxy SIII, SIV, Note, Note II and Note 10.1) without impacting compatibility with other devices.

Adding support is so easy that it doesn’t make a lot of sense to provide patches see http://www.modaco.com/page/news/_/android/developers-add-support-for-samsung-multi-window-to-your-apps-r823 and http://developer.samsung.com/s-pen-sdk/technical-docs-09.

OSMAnd has just added support, and I have patched OSMtracker and vespucci versions available.

Note: I have no affiliation with Samsung other than owning a couple of their devices.