iPhone Screenshots


The MK61+ application is an advanced programmable RPN calculator. It has powerful features and easy to use at the same time.

While the app is based on Electronika MK61 calculator, produced in 80-90s of the last century, it is not an exact emulator of its prototype. It was created with intention to get a handy tool to use on daily basis. So, some extra functionality was added, that was absent in the original calculator, some quircks of the original MK61 were fixed.

The main calculator features are the following:

• Authentic look and feel.
• Good balance between powerful features and simplicity of use.
• All-encompassing help system including Quick Help and Calculator Reference.
• Quick State panel to get insight into calculator's state.
• Ability to save and load programs. The programs can be loaded at arbitrary address in memory.
• Rich capabilities to create and edit programs in Program Code view.
• Support for input and output operations of data files.
• Operating stack with 5 registers and 15 indexed registers to store intermediate results.
• Program memory with 160 cells, that is more than enough for most practical tasks.
• Rich set of instructions including ones for subroutine calls, jumps, loops and their indirect counter-parts.
• Support of hexadecimal and binary numbers (such numbers can contain up to 10 digits).
• Copy-paste operations with a quick tap on the calculator display.

View more calculator's screenshots on http://joyful-apps.com

What’s New

Version 2.5.2

• Fixed bug: it was not possible to save data files. Thanks to Alex Wilpert for the report.
• The minimal IOS version is 7.1.

Ratings and Reviews

Swanflyer ,

Clever and useful

One of my favorite RPN calculators. Good looks, simple display basically shows X-register, but entire contents of stack and memory are easily accessible. Easy to program, with comprehensive instructions built in. Has a relatively light memory footprint, good for devices that are short on memory. Keyboard is a little disconcerting at first because it doesn't appear to have an enter key, but it's there - it's just labeled X with an up-arrow next to it. A little different from traditional RPN calculators but fun to use and all the same functionality is there.

SamLazy ,

The best RPN calculator!

Thank you! If you make MK-52 I'll buy without hesitations!

DrCoyote ,


I don't always have my MK52 with me, but I always have my iPad! This app does a great job emulating the wonderful MK61, one of my favorite calculators of all time. Everything is faithfully emulated, except the speed. ;)

This app also adds a lot of thoughtful, useful programming tools the MK never had. Thanks for the eat work! How about an iPad version? MK61 in portrait orientation, MK52 in landscape?


Alexander Skobelev
5.1 MB
Requires iOS 7.1 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 2015 Alexander Skobelev


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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