# goRPN > RPN calculator emulating HP-16C, open-source, for utilities. (iPhone/iPad app by Joel Perry.) - Source: https://appshunter.io/ios/app/gorpn/id1212060693 (this page in markdown: same URL + `.md`) - Developer: [Joel Perry](https://appshunter.io/developer/972887837) - Category: Utilities - Price: Free - Rating: 3.00/5 from 1 App Store ratings · 1 written reviews indexed - Age rating: 4+ - Requires: iOS 9.0 · 12 MB - Languages: American English - Released: 2017-03-07 - Data updated: 2026-06-01 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/gorpn/id1212060693/reviews.md ## What is goRPN? goRPN is an RPN calculator, with a stack modeled on the HP-16C. It is currently quite minimal, but will eventually adopt more of the functionality of the 16C. goRPN is open-source software. If you would like to contribute, get the source at https://www.github.com/joel-perry/goRPN ## Key features - RPN calculator - HP-16C stack emulation - Open-source software - Minimalist design - Future functionality expansion ## Recent user reviews (1 of 1) All indexed reviews: https://appshunter.io/ios/app/gorpn/id1212060693/reviews.md ### 3/5 — Not bad, but no 16C *2018-12-14* Does a pretty good job as a RPN calculator. I only tried the basic four function. Tried to string calculations together: 166 / 60 * 2 * 6 but wasn’t able to. I would get the first calculation, but wasn’t able to push the result to the stack. I tried to press [Enter], but there was no response Tried to use a function key (+ or / or *) and that wouldn’t work either. Also didn’t like that if force my iPad to portrait orientation. Found no settings to change this. Okay, so what do you want for free? Please sir (or madam) a little more functionality please. I deleted my copy, but will keeping my eye out for updates. The author needs to add a way to push and rotate the stack. There should be a memory button to store results regardless of stack, and lastly a way to change the orientation to landscape based on the accelerometer. In landscape, the buttons should go on one side, and the stack and answer should go on the other. ## Frequently asked questions about goRPN ### What is goRPN? goRPN is a free, open-source application that functions as a Reverse Polish Notation (RPN) calculator. It aims to emulate the stack behavior of the HP-16C calculator. ### Is goRPN free to use? Yes, goRPN is completely free to download and use. It does not feature any in-app purchases or advertisements. ### What devices does goRPN support? goRPN is currently supported on iPhone and iPod devices. It is not specified for Android or other platforms. ### How often is goRPN updated? The application was last updated on March 7, 2017, with version 1.0. Further updates will depend on developer contributions to the open-source project. ### What is the age rating for goRPN? goRPN has an age rating of 4+, making it suitable for users of all ages. This rating typically indicates no mature content. ### Can I contribute to goRPN? Yes, goRPN is open-source software. You can find the source code on GitHub at https://www.github.com/joel-perry/goRPN and contribute to its development. ### What is the user sentiment for goRPN? Based on the available data, goRPN has a rating of 3.0 stars from 1 rating. This indicates a limited amount of user feedback currently. ### Does goRPN have ads? No, goRPN is ad-free. As an open-source utility, it does not contain any advertisements. ## Version history (last 1 release) ### 1.0 — 2017-03-07 This app has been updated by Apple to display the Apple Watch app icon. ## Apps similar to goRPN | App | Rating | Price | Category | | --- | --- | --- | --- | | [bcRPN](https://appshunter.io/ios/app/bcrpn/id1614744829) | 4.8 (4) | Free | Utilities | | [RPN Calc](https://appshunter.io/ios/app/rpn-calc/id285002799) | 3.3 (4) | $0.99 | Utilities | | [Calccis](https://appshunter.io/ios/app/calccis/id6446233205) | — | Free | Utilities | | [ThetaCalc](https://appshunter.io/ios/app/thetacalc/id1521614636) | 4.3 (4) | Free | Utilities | | [HP-35](https://appshunter.io/ios/app/hp-35/id6738010641) | 5.0 (5) | Free | Utilities | | [SwiftRPN](https://appshunter.io/ios/app/swiftrpn/id6470951024) | — | Free | Utilities | ## More apps by Joel Perry - [DelayTool: BPM Calculator](https://appshunter.io/ios/app/delaytool-bpm-calculator/id982070192) All apps by Joel Perry: https://appshunter.io/developer/972887837 ## Related topics [gorpn](https://appshunter.io/ios/topics/gorpn) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-01.*