Andy, the calculator is just a simple Excel spreadsheet. You can use it on anything that will run Excel.
For anyone wanting the stand-alone version, The speadsheet is available for download as a zip file on Mark Forsyth's thread here.
My version is just a web conversion of the speadsheet. It has the advantage it will run on any browser on a range of hardware without Excel, but of course you need an internet connection.
It works just fine at our field on my iPhone using the mobile phone connection. Data traffic is very small.
Originally Posted by Andy from Sandy
Thank you Wayne.
I have now got the calculator running standalone on my PC. I carry a small netbook to the field so I can install it on that.