As I understand it, UVMapper reads a text file and does its best to make sense of it as an OBJ format mesh. Although you can only open a *.OBJ file from the file menu, you can drag-and-drop anything you like onto the program; any Poser file which has embedded geometry, such as PP2 and HR2 files will work this way for instance. So yes, it is an excellent tool for beautifying OBJ files. The Pro version also has a 3D preview, as well as a means of selecting various malformed facets which is very handy when trying to work out why your seemingly smooth mesh renders with horrible black splotches on it (to quote a recent experience of mine).