The program 'UnitConverter' is GPL-freeware, offered for download on this website.
UnitConverter is a simple and compact conversion utility for more than 700 units and unit combinations.
The converter was extended by the unit millibar in the combination "force per area" and a conversion error in the combination "volume flux" for dm3 to mm3 was fixed.
You find the 'UnitConverter' here.
The Website is here.