Hello,
SDVFR is an application available on android and IOS.
It can be interfaced with flightgear via the foreflight-xgps.xml protocol file found in the Protocol folder of FGdata.
Add an option at the start of FG
--generic = socket, out, 1,255.255.255.255,49002, udp, foreflight-xgps
In the options of SDVFR activate Simulator Mode.
Track your flight in a GPS and record the track.
Enjoy.