GO-25 SciRPN 4+

Stephen Lidie

    • 5.0 • 3 Ratings
    • $4.99


GO-25 SciRPN simulates the venerable HP-25C Programmable Scientific Calculator from 1976. Virtually indistinguishable from the real item in operation, GO-25 is a powerful yet simple retro calculator.

• RPN (Reverse Polish Notation)
• 10-digit LED calculator display, 10-99 to 10+99
• Four stack registers with roll down
• Ten storage registers with arithmetic memory operators
• Math, trigonometric, polar/rectangular, sexagesimal/decimal, logarithmic, statistical, power and other miscellaneous functions
• Programmable, with annotated program listing, and memory for 99 program steps
• Library of Sample Programs
• Fast, slow or single step program execution
• Program import via pasteboard or from other Apps
• Program export via printer, email, pasteboard or to others Apps
• iTunes program File Sharing
• Two additional windows with views of:
◦ stack/storage registers
◦ keystroke log
◦ program source code
◦ program documentation
• Copy-from and Paste-to the calculator display
• Simple Paper Tape annotations

What’s New

Version 4.5

- Support iPhone 14; cosmetic improvements for iPhones 5, 6, 7 and 8.
- Update for iOS 16, macOS 12.6, tvOS 16.

Ratings and Reviews

5.0 out of 5
3 Ratings

3 Ratings

sonarman ,

I wish I’d found it sooner!

This is a wonderful simulation and has become the go-to calculator on both my iPhone and iPad. If I had found it years ago I might have saved myself a fair bit of money and time spent on other calculator apps.
If you like to use RPN calculators and keystroke programming, this one deserves your attention.
Pros - it’s a calculator first and foremost. There is no CAS or graphing to bloat the app. The stack and program listing windows make keeping track of things very easy. It looks good and the settings are straightforward and useful (thank you for allowing the option to mute the key sounds).
Cons - none so far.

RandyAtKC ,

Old HP-25 user

I’m very impressed with this program. With the latest update I’m starting to like this app as much as the original calculator. If only the keyboard was the same...

brianrhill ,

Amazing Rendition

When the on-off switch on my 25C gave out I got a 32SII.

For those that had a 25C, the faithfulness of this rendition is amazing.

I prefer the 25C emulation to a 42S emulation because it is more Spartan. For those that want more keys to fat-finger (37 instead of 30 is noticeably more crowded) and more programmability (why when for anything serious you have something like Mathematica?) there are at least two emulations of the 42S on the App Store.


The tiny green LEDs, the blue info button, and the fact that the iPhone's status bar are not hidden all distract from the purity of the experience. How about an super-retro mode where all those are gone?

A more evocative app icon? Maybe just 0.00 in red LEDs?

I didn't find either of the keystroke sounds satisfying so I had to turn sounds off. The 25C had a padded yet definite click that I guess is hard to duplicate.

Needs some finger grime and a flaky on/off switch to be like I remember.

App Privacy

The developer, Stephen Lidie, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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