Free in the iTunes app store is iDiscount which calculates sale discounts easily while out shopping those great sales with multiple discounts.  iDiscount is great when there is an item that is already 45% off and then you can take an additional 10% off.  It also figures in sales tax.  What more could you ask for?

Oh, a unit cost calculator for the grocery store, iDiscount has that.  How about figuring out how much a 1/2 pound of turkey costs, just put in the price per pound and select weight.

I looked at the comments and there seemed to be a problem in the past with calculations.  It looks as though that problem is fixed and calculations are right.

If you are looking for a free app for calculating discounts then check out iDiscount and let me know what you think.  Do you use another application for discounts that you would like to suggest?  Leave me a comment.

App:  iDiscount