CoPilot with FlightMaster for the Palm Pilot devices. CoPilot is the planning application (does W&B and all sorts) and integrates with the Moving Map GPS part which is FlightMaster.
Download from
http://www.flight-master.com/download.html Additional databases available from:
http://www.flight-master.com/database.html
Been using it for years and it does the job IMO.