# RPN-70 HD — Very rare vintage calculator > Photo-realistic simulation of the rare HP-70 vintage financial calculator. (iPhone/iPad app by Willy Kunz.) - Source: https://appshunter.io/ios/app/rpn-70-hd/id436127144 (this page in markdown: same URL + `.md`) - Developer: [Willy Kunz](https://appshunter.io/developer/424873503) - Category: Productivity, Finance - Price: Free - Rating: 5.00/5 from 3 App Store ratings · 15 written reviews indexed - Age rating: 4+ - Requires: iOS 12.0 · 14 MB - Languages: American English, German (Germany) - Released: 2011-05-17 - Data updated: 2026-06-01 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/rpn-70-hd/id436127144/reviews.md ## What is RPN? RPN-70 HD is a complete, photo-realistic simulation of the financial hand-held calculator HP-70 from 1974. It handles loan amortization, saving plans, depreciation, and much more with ease. What users said: "Hard to find a decent calculator on iPad, try this one." "I don't normally write reviews but RPN-70 is just too fantastic to not get excited about. Apple should list this app under their Education category in the App Store and make it a must have for every college bound student. It is the best HP emulator in the market." "An incredibly well-engineered calculator app, and free, to boot!" "This is a really cool Financial calculator. Just like using the original HP-70. Accurate to the penny." Features: • Photo-realistic look based on an existing device • "Live" register view in landscape mode • Animated keys with click sound (adjustable volume) • All functions and operations of the HP-70 fully implemented • Simulation of the HP-70's computation time (optional) • Correct wrong number entries by swiping left across the display • Cut/copy/paste of display value • Visual indicators keep track of stored input parameters (optional) • Stack shown right below display (optional) • 10 non-volatile memory registers (optional) • Built-in short manual with many examples The HP-70 was discontinued after just one year. It is one of the rarest calculators, hard to find in any condition. NOTE: RPN-70 HD is a faithful simulation of a vintage HP-70 calculator, as has been verified against a real device using the examples in the Applications Cookbook section of the HP-70 manual. In certain cases, what may appear like a bug of the app is actually an idiosyncrasy of the HP-70. IMPORTANT: The HP-70 requires exactly three input parameters from the top-row keys, at least one of them being either "n" or "i". In other words, you can't use PMT, PV, and FV as input parameters simultaneously. A version for the iPhone named "RPN-70 SD" is also available. Visit the website: www.cuveesoft.ch ## Key features - Photo-realistic design - Live register view - Animated keys with sound - Full HP-70 function implementation - Cut/copy/paste display value - Built-in manual with examples ## Recent user reviews (10 of 15) All indexed reviews: https://appshunter.io/ios/app/rpn-70-hd/id436127144/reviews.md ### 5/5 — Top notch! *2020-06-03* This app not only reproduces the HP-70 but improves upon it by adding options for the display and making excellent use of iPad's computing power. As if that's not enough, it's also an education! – It comes with comprehensive examples which cover every imaginable purpose. Huge thanks to the developer whose perfectionism is not lost on me. P.S. One tiny improvement (for me) would be an option to choose a plain background. ### 5/5 — Definitely a five star APP *2020-04-13* I just love RPN and have used it with my original HP12C which still works. This APP clones the HP exactly and I highly recommend this calculator. ### 5/5 — Beautiful Emulation ! *2019-02-08* Beautiful Emulation of a classic. I love this app and it’s iPhone companion as well. Wonderfully designed and true to the original. ### 5/5 — Great *2014-10-08* Hard to find a decent calculator on iPad, try this one. ### 5/5 — Faithful replica of an old favourite *2014-05-16, version 2.0* This App faithfully recalls an old favourite rpn calculator and it works very well. It's my favourite calculator on my iPhone. ### 1/5 — No landscape mode...useless! *2013-06-02* Why assume that everyone will use this in portrait mode? No way to change it that I can find. Deleted... ### 5/5 — Simply amazing *2013-02-19* I don't normally write reviews but RPN-70 is just too fantastic to not get excited about. Apple should list this app under their Education category in the App Store and make it a must have for every college bound students. It is the best HP emulator in the market. If you are a fan of HP calculators, this is it, and it is free!! Thank you CuVee. Now is it too much if I ask for an iPhone version? ### 5/5 — Perfect *2012-08-17* Exactly what I was looking for. A real HP RPN machine. ### 5/5 — Love it! *2012-06-13, version 1.0.3* I've always loved HP calculators and this is a lovely and nostalgic simulation. Nice job! ### 5/5 — Awesome Calculator ! *2012-06-08* This is a really cool Financial calculator. Just like using the original HP-70. Accurate to the penny. Hmmm, I wish they'd come out with a version for my i-Phone. Happy to pay for it. Great job! ## Frequently asked questions about RPN ### What is RPN-70 HD? RPN-70 HD is a complete, photo-realistic simulation of the financial hand-held calculator HP-70 from 1974. It is available for iPad and offers all the functions and operations of the original device. ### Is RPN-70 HD free to use? Yes, RPN-70 HD is completely free to download and use. It is also ad-free and does not feature any in-app purchases, providing an uninterrupted user experience. ### What financial calculations can RPN-70 HD perform? RPN-70 HD handles loan amortization, saving plans, depreciation, and much more with ease, just like the original HP-70. It is verified against a real device for accuracy. ### Does RPN-70 HD have ads? No, RPN-70 HD is ad-free. Users can enjoy the full functionality of the vintage calculator simulation without any advertisements interrupting their workflow. ### How accurate is RPN-70 HD? RPN-70 HD is a faithful simulation of the HP-70, verified against a real device using examples from the HP-70 manual. It is accurate to the penny for financial calculations. ### What devices does RPN-70 HD support? RPN-70 HD is designed specifically for the iPad. A separate version, RPN-70 SD, is available for the iPhone. ### How often is RPN-70 HD updated? RPN-70 HD was last updated on July 28, 2025, indicating ongoing support and potential for future improvements or compatibility updates. ### What is the age rating for RPN-70 HD? RPN-70 HD has an age rating of 4+, making it suitable for a wide range of users, including students and professionals interested in financial calculations. ## Version history (last 5 releases) ### 3.4 — 2025-07-28 • All registers are now non-volatile. • Double-tapping the display acts like the View/Registers button (bottom-right). • Triple-tapping the display: - Clears registers R0..R9 (only if enabled in Settings). - Resets the register K to 12. ### 3.3 — 2025-05-09 • Faster startup – no delay until the first button press is recognized after switching on. ### 3.2 — 2024-11-07 • RPN-70 HD runs on Apple Silicon Macs (see notes on homepage cuveesoft.ch). • Disabled low-battery indicator (all decimal points lit) when running on Apple Silicon Mac. • RPN-70 HD requires iOS 12 or later. ### 3.1.5 — 2022-11-09 • iPadOS 16 compatibility ### 3.1.2 — 2021-10-03 • iPad mini (2021) compatibility ## Apps similar to RPN | App | Rating | Price | Category | | --- | --- | --- | --- | | [Fairy PDF Reader](https://appshunter.io/ios/app/fairy-pdf-reader/id1620695357) | 5.0 (2) | $2.99 | Productivity | | [i41CX+](https://appshunter.io/ios/app/i41cx-plus/id289068865) | 4.8 (100) | $24.99 | Productivity | | [WP 31s](https://appshunter.io/ios/app/wp-31s/id973621300) | 4.9 (15) | Free | Productivity | | [DB50X](https://appshunter.io/ios/app/db50x/id6625971367) | 5.0 (7) | $9.99 | Productivity | | [WP 34s](https://appshunter.io/ios/app/wp-34s/id620255094) | 4.7 (28) | Free | Productivity | | [DB40X](https://appshunter.io/ios/app/db40x/id6624315901) | 4.7 (7) | Free | Productivity | ## More apps by Willy Kunz - [RPN-45 HD](https://appshunter.io/ios/app/rpn-45-hd/id424873500) - [Smart Sudoku](https://appshunter.io/ios/app/smart-sudoku/id457564906) - [Vintage-45](https://appshunter.io/ios/app/vintage-45/id506402272) - [RPN-45 SD](https://appshunter.io/ios/app/rpn-45-sd/id509923051) - [RPN-67 NP](https://appshunter.io/ios/app/rpn-67-np/id603100249) All apps by Willy Kunz: https://appshunter.io/developer/424873503 --- *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.*