it's a script that let's you drawn new topography over high poly mesh.
something like you sculpt you model in Z or Mud import it to max turn the script on and you can easily drawn a low poly mesh over it that wil snap it self to your high poly model.
basically you can use this as a mesh simplifier, but then made by hand (the mesh) instead of a random algorithm. Will download and see how this goes. It does look like it'll only be usefull for organic models due to the free hand nature of it.