“Go Calc” ($9.99 on the App store) is a great and easy to use calculator app that allows your to customize you calculator with any formula you would like! You can create a calculator for any type of problem, with formulas used that are similar to those found in desktop spreadsheets, such as Microsoft Excel.
Go Calc can be used by just about anyone. Feel free to set your own variables and create any type of calculator you may need. You may also use the many calculators that are built into the app already! Go Calc includes the ability to export / import your custom calculators as xml files, making it a simple and fast way to share information with customers or friends.
This app makes it extremely easy to create a custom calculator on your iPad or iPhone for ROI calculations for SMS. It comes in handy if you are with a customer and want to show them some what-ifs on their ROI variables.
-XML File examples
Roy already created this XML file for your convenience so just import it and you are ready to go!