To celebrate my calculator app PCalc turning 30 today, I've written up all the history I can still remember:

http://pcalc.com/thirty

There's also a rare 30%-off sale, which runs until midnight tonight, PST.

Mac:
https://apps.apple.com/us/app/pcalc/id403504866

iOS:
https://apps.apple.com/us/app/pcalc-the-best-calculator/id284666222

A big thanks to everybody who has used PCalc during the last three decades!