Unfortunately Mr Schedule and the pietschy.com website disappeared. I made my own recreation using REALbasic / Xojo at the time, but never released it and faded from using it.
Joel Spolsky expanded the idea later with Evidence Based Scheduling:
https://www.joelonsoftware.com/2007/10/26/evidence-based-sch...
That takes the estimates from Painless Software Schedules, but runs a Monte Carlo simulation using your estimates & data on actual time taken, to create a confidence distribution curve graph of when you'll be finished.