RPN 28x Calc is a scientific calculator that creates a unique user experience where you can interact with your operands by touching them in the display.

It is a reverse-polish notation (RPN) calculator with a dynamic stack display that automatically expands such that you can see up to 16 levels at a time. For more levels, you can easily scroll through the stack by swiping up or down across the display.

Advanced commands are available in the secondary panel. The buttons are efficiently grouped into four pages that you can quickly navigate with a swipe of your finger:

- letters A-Z for typing,
- trigonometric, logarithmic, and variable commands,
- statistics, arrays, lists, and string manipulation,
- binary numbers and boolean logic.

This is why RPN 28x Calc is unique in its class:

- You can tap a row to select it and issue commands for the selected level.
- It is possible to rearrange the operands with the touch of your finger.
- The display automatically resizes to show up to 16 levels of the stack.
- You can swipe up or down the display to see more than 16 levels.
- You can slide the secondary panel out of view or swipe across the panel
to navigate between button pages.
- When you enter a value, you can tap a digit to reposition the cursor.

RPN 28x Calc is all you need.

- High precision arithmetics.
- Supports multiple data types: real numbers, binary numbers, lists, arrays
or vectors, names, and strings.
- Retina-resolution graphics for the new iPad.
- Support for landscape orientation.
- No ads.
- Downloadable user guide with introduction and command reference (PDF).


Plans for future versions (NOT YET SUPPORTED):
- Support for programs.
- Complex numbers.
- Matrices, i.e. arrays within arrays.
- Arithmetic expressions.