Flight Planner is one of major improvement achieved by FSX.
Universal Avionics Systems Corporation
Allows you to perform offline GPS FDE predictions for remote/oceanic operations.
Aerosoft Flight Calculator does all the calculations you need during your flight.
Traffic X is an add-on for users of Microsoft Flight Simulator FSX.
All your favorite Flight Sim sites are all a click or two away!
Just Flight Ltd
VLJ Business Jet is an add-on for users of MS Flight Simulator FSX or FS2004.
Champagne PC Services
Flight Planner 3000 is a program which produces detailed, accurate flight plans.
Garmin Ltd or its subsidiaries
Transfers flight plans from your computer to the flight plan data card.
Offers various information screens like Flight Tracking, Flight Plan, etc.
Add pilot information to obtain weather briefings and file a flight plan.
Plan-G is a VFR flight planning tool for Microsoft Flight Simulator.
Plan and review your travels with this GPS mapping tool.
Load IGC flight files and terrain imagery to plan flights.
Delta Virtual Airlines
Delta Virtual Airlines A330 (FS2004) is a Airbus plan for flight simulations.
APM Planner helps you plan your flight path for the next mission.