Calc-Lua - RPNプログラミング電卓 app for iPhone and iPad
It is the customization possible reverse polish notation (RPN) portable calculator.
Method of using differs from the normal portable calculator.
In addition, also it is possible to define the function which in programming language "Lua" is written programmable key.
Also it is possible to build up your own sufficient special portable calculator by the fact that name and macro are changed in the key where the function is allocated already.