FreeCalculator

FreeCalculator is the complete RPN calculator for Android.

It includes

* reverse polish notation calculator with about 100 functions (standard, trigonometric, logarithmic, hyperbolic, matrix, logic, number theory, ...)
* unit-conversion and calculation (us, imperial and international unit system)
  for example: enter 5 foot, enter 4 inches, multiply and you will get 1.66 sq.ft
  supports SI-prefixes: Enter 5 volt, enter 200 micro ampere and divide them! (Hint: Its's 25 kΩ)
   define your own units and use them just like system units!
* complex numbers in algebraic or exponential display mode (argument in radian or degree)
   Mix them with real numbers in two argument functions (add, div, ...)
   See and enter the argument in radian or degrees, depending on trigonometric mode
   Please be aware of the complex mode when entering data; don't assume it is always a+bi !
* (large) integer numbers with
   logic (shift, rotate, set, clear, ...) and
   number theory functions (n!, factorisation, isPrime, nextPrime , ...)
   use them in (most of) the existing functions.
   logic and some arithmetic functions unbounded or with a fixed word length
* full support of matrix (and vector) operations (real and complex) plus
   determinant, trace, transposition, inverse, power
   matrix norms: column sum norm, row sum norm, spectral norm, frobenius norm, maximum norm
   LU- and QR-decomposition (inspect L,U and Q,R if you want) for solving linear equations
   (Eigen values and eigen vectors of a matrix)
   (Matrix functions: Matrix exponential (pade approximation))
* (data transfer to other devices)
   easily transfer all your data to other devices. No need to re-enter everything when changing devices.

It is easy to use

* assign the buttons the functions you want with a simple swipe of your finger!
* reorder stack entries by dragging them
* (record macros to simplify often used routines)
* extensive built-in help
* permanent register storage for your constants etc.
* (transfer your data to another device)
* full undo functionality
* no limits on stack or register storage
* full support of degree-minutes-seconds formats (including calculation!)
* number system: floating point or integer
* number formats: four floating point formats as well as decimal, binary, octal and hexadecimal for integers.

This is the free version

* no advertising (yes: NO ADVERTISING in the free version!)
* limitations: Your self-defined button assigments will not be saved. Your macros will not be saved. You may not export or import data. No usage of complex numbers in trigonometric or logarithmic functions, no and/or/not/xor, modulo (et.al.) for integer numbers. No eigen values or matrix exponential.

Have a look at the definition of a function or conversion by clicking the entry in help->list of functions/conversions.
This calculator is designed for a screen width of at least 400 pixels.
It's reverse polish notation, so there is no "="!