Did you know that Microsoft Excel for iPhone and iPad users is a free download on iTunes? It is!
The current version of Microsoft Excel for iPhone/iPad users is 1.13.1. And while the mobile version is understandably not as robust and full-featured as the regular desktop version, the mobile version is still amazingly good. Best of all, the mobile version of Excel includes the built-in statistical functions on which Statistical PERT is based (NORM.DIST and NORM.INV).
Try downloading an example workbook from the Statistical PERT website using your iPhone or iPad. (Be sure to download and install Excel on your iPhone/iPad firstly). Then, open the SPERT download file in your mobile version of Excel, and start estimating!
Here’s what Statistical PERT looks like on my iPhone 5S (with a few columns hidden so I can make Planning Estimates and see their probabilities):