What I want is a phone app calculator that works like the Python REPL/console. Save ALL previous calculations. Display the last dozen or so. Can scroll through them. Tap on one to recall it, edit one number, recompute. Done.

This would beat by far the convenience and usability of this 2-in-1 calculator. I would KILL to have this.

In fact, on my laptop, I use the Python REPL as a calculator. I hit Ctrl-T python ENTER. It opens a terminal and I start typing 48*152 ENTER and I see the result. The history of calculations is saved. I can access previous calculations, edit one number and recompute. I see the last 100 lines or so, on one screen.

The only one somewhat usable Python REPL on Android is "Pyonic Python 3 interpreter" but it's clumsy to use as a calculator because it uses the standard alphabetic keyboard so you have to keep switching to the special characters layout to type math operators (-+/...) If this ONE detail would be fixed, and with some minor UI polish I believe it could become more popular than the 2-in-1 calculator...