Look at
http://forum.free-track.net/index.php?showtopic=1508
I agree with you that such information is mainly missing.
There is a reply from me in english.
If you use Delphi to program look at the source code at
https://camil.dyndns.org/svn/freetrack/tags/V2.2/FreetrackClient/
FreeTrackClient is a library, that exports some functions to get the position information from freetrack.
freetrack_c_interface.cpp
Is just an example to use that DLL library from C++. Although it is right now outdated as I've explained in the previous reference.
Cheers,
Javier