The crazy calculator (RPN mode). Once you get used to it, you will love it :-)

Dib2Calc (aka Dibdib Calculator)
The crazy calculator. A short introduction is provided when you start it for
the first time.
The goal is to provide many specific functions, especially for text data and
data structures, not only for calculating numbers. This is one of the reasons
why it makes use of the so-called RPN notation: instead of typing 4 '+' 3 '=',
you type 4, 3, '+' (but you can also type 4 5 6, 3, '+' resulting in 7 8 9,
because 7=4+3, 8=5+3, 9=6+3 ...)
Just try it out. Once you get used to it, you will love it :-)
Your data is protected (encrypted) if you use your own access code and
password. In case you have a lot of data, make sure to save it to the device's
Download area via the SAVTO function (as a backup).
See https://gitlab.com/dibdib/dib2calc for more information (and
https://gitlab.com/dibdib/dib2calc/-/blob/master/known_issues.md for
known issues).
WhatsNew:
- Version 0.24.30 (alpha software!, not thoroughly tested).
- Calculation of leap seconds adjusted.