Kalkulon is a programmable expression calculator for programmers available for your Windows, Linux and Android device.
If you just need a simple calculator Kalkulon is probably not what you are looking for.
But if you are looking for a scientific calculator with the following features
* C-like syntax, e.g.: (0x10>>3)+(6|4)*7
* variables, e.g: bitmask = 0x0F0F; 0x1234&bitmask
* user defined formulas and scripts, e.g.: AddMul(a,b,c)=(a+b)*c; AddMul(1,2,3)
* fully programmable, e.g.: if, while, do, etc.
* result history (out, outl), e.g.: 3+4; out+8; outl[0]+outl[1]
* casts, e.g.: ((u8)-1)