Funky TAX Calculator is an Adobe AIR application, a tax calculation utility that lets you visualize how much money you owe. It displays the tax amount, while also allowing you to include tax information. Basically all that you have to do is enter the invoice amount and this tool will take care of the rest.
So, if you want to be able to monitor the money you owe without much fuss, take TAX Calculator for a spin and check out if its capabilities respond to your needs.

Requirements:
* Adobe AIR

The license of this software is Freeware, you can free download and free use this accounting software.