Stackis RPN

【2026.03.24iOS限免】

This is an RPN calculator in the style of, for instance, old HP models. It will feel familiar if you are used to RPN, otherwise it will probably be a little confusing at first.

It's not programmable and it doesn't try to mimic older hardware; it's just meant to be a pleasant calculator for those who prefer to use RPN.

Also, if you want to perform calculations in duodecimal (dozenal), this app is for you!

Stackis is still a baby -- please help us by reporting any bugs or weirdness that you encounter. Any suggestions for improvements are very welcome!