Finishers
Very similar to modifiers, but logically mostly for applying final modifications to objects.
Polygonizer
Reconstructs polygons from triangles
Heal and Optimize
Polygon reduction and mesh optimization modifier
Polygon Reducer
Polygon reduction, mesh heal and mesh optimization modifier
Fix Faces Orientation
If object has faces with wrong orinettaion, this modifier may try to correct this mistake
Remove Internals
Modifier may remove non visible parts.