@jamesthomson One possible suggestion for post-sale revenue for PCalc is additional calculators. You already have several types, which is already awesome.
A construction calculator (a la the Construction Master) is a significant enough part of my usage that I’d pay for an add-on.
Or I wonder if people are interested the functionality of the HP 12-series.
Pay for the app and have add-on purchases.
Just a thought after your recent appearance on Upgrade.
Today at work I had to review a document. Half of it was set in Helvetica and half was in Arial. I’m pretty sure I handled it better than @gruber would have.