Tips - Not able to input sales tax

The application shuld calculated on the amount without sales tax. It did not even let you input sales tax percentage. So subsquently the calculation is wrong. I can not believe all the people rated this so good. It does not worth the charge. The free one that you can input sales tax.
Do not buy a application without even know that the tips should not be on the total including sales tax.

Corinna101 about Tips, v3.2