I think it’s a neat mix of novelty and practicality that a lot of people are unaware of.
I use a TI-83 Plus and ripped my ROM using TiLP and now use TilEM on my Linux machine and Graph89 (available on F-Droid) on my Android device. The hardest part was getting a hold of a TI Graph Link cable.
Setup generally depends on your calculator and which device you wish to emulate it on (Linux, Windows, MacOS, or Android).
The matching familiar layout can sure save time versus learning whatever the landscape version of the default calculator app on your phone has to offer.