There is a hugh variety of post-processing options in GASFLOW. There is even a built-in graphical output. However, this might be abandoned in the future. With the standard netcdf format interfaces or direct use for many postprocessors is possible. There are users applying AVS/EXPRESS and tecplot.
In the current version there are dedicated interfaces to gmv and openDX integrated. The latest version of the User's Manual contains short descriptions how to steer GASFLOW to generate suitable output.
The GASFLOW team is not able to provide support for these post processors.