I was pretty delighted to realize I could now delete the lame Calculator.app from my iPhone and replace it with something of my choice. For now I've settled on NumWorks, which is apparently an emulator of a modern upstart physical graphing calc that has made some inroads into schools. And of course, you can make a Control Center button to launch an app, so that's what I did.
Honestly, the main beef I have with Calculator.app is that on a screen this big, I ought to be able to see several previous calculations and scroll up if needed. I don't want an exact replica of a 1990s 4-function calculator like the default is (ok, it has more digits and the ability to paste, but besides that, adds almost nothing).
Calculator.app does have history now FWIW, it goes back to 2025 on my device. And you can make the default vertical be a scientific calculator now too.
Also it does some level of symbolic evaluation: sin^-1(cos^-1(tan^-1(tan(cos(sin(9))))))== 9, which is a better result than many standalone calculators.
Also it has a library of built in unit conversations, including live updating currency conversions. You won’t see that on a TI-89!
And I just discovered it actually has a built in 2D/3D graphing ability. Now the question is it allows parametric graphing like the MacOS one…
All that said, obviously the TI-8X family hold a special place in my heart as TI-BASIC was my first language. I just don’t see a reason to use one any more day to day.
I haven't reinstalled it to check how it's implemented, but I want that history visible on the screen. So that I can do 3 calculations, then look up and see the calculations and results, for instance, to copy them down somewhere.
I'd like multitasking too with multiple apps visible at once so I could copy figures easily from one app to another, like the Android I tried in 2020, but obviously that's asking too much of Apple.
I looked at that calculator. But HP Prime and TI-89 have CAS systems that can do symbolic math, so I prefer to emulate them.