FileBox xEtender is very good app, if any one can change this into portable app. This is no longer supported by developer, but source code is also made available by developer.
Program: FileBox xEtender
License: Free product released under GNU General Public License, including the source code
Website : http://www.hyperionics.com/files/
Best thing about this software is "Click-Switch" file folder feature, which I could not find in any other software.
With "Click-Switch" feature it switch to any opened folder you click on, in file save as or browsing file folder.
It is very handy if someone works with multiple folder opened most of time and can go direct to particular folder with one click on that folder instead of browsing in file save as window.
This feature is not working properly in some latest softwares. Or is there any other portable app has this feature already ?