Mac Flight Planner is the first, and at the time of writing the only, flight planning application aimed at real aviation. If you are looking for a flight planner for X-Plane then try Goodway
. They are both well supported. However if you are a pilot in the real world then you will probably find Mac Flight Planner much more useful as you aren't bound to the X-Plane database of waypoints which is very comprehensive but not accurate enough for real flight in all parts of the world (I'm sure Austin couldn't guarantee that they are accurate enough for real flight in any part of the world).
MFP now also features a database utility for importing and exporting waypoints.