i48 vs RPN
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
i48
This application emulates the HP48GX calculator on your iPhone or iPod touch. It allows you to perform complex calculations like matrix operations and function integration on the go.
- HP48GX calculator emulation
- Matrix calculations
- Function integration
- Mobile calculator
- On-the-go calculations
Read full descriptionHide full description
i48 is an emulator for the HP48GX calculator, so the next time you're out and about and need to do some quick matrix calculations or work out the integral of a function, just whip out your iPhone (or iPod touch) and have at it
RPN
This app is a faithful simulation of a rare 1974 financial calculator, offering all its original functions with enhanced features like more memory registers and a visual stack display. It's designed for users who appreciate vintage technology and need precise financial calculations.
- Photo-realistic vintage calculator design
- Full HP-70 function simulation
- Animated keys with sound
- Enhanced stack and memory register view
- Cut/copy/paste display value
- Input parameter visual indicators
Read full descriptionHide full description
RPN-70 SD is a complete 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: "Looks good, all functions you need. Love it!" "This is a beautiful emulation of a very rare HP financial calculator from 1974. Works just like the original but better! Faster, more accurate, with 10 more storage registers, and a popup window lets you see the contents of each stack, financial and storage register. Provides TVM4 functionality for compound interest as well as accumulated simple interest. A true work of art!" Features: • Photo-realistic look based on an existing device • Animated keys with click sound (adjustable volume) • All functions and operations of the HP-70 fully implemented • Correct wrong number entries by swiping across the display • Cut/copy/paste of display value • Double-tap display to view the stack and memory registers • Visual indicators keep track of input parameters entered • 10 non-volatile memory registers (not available in original HP-70) 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 SD 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 HD" is also available. Short manual and sample calculations on the website: www.cuveesoft.ch
Screenshots
Verdict
The clearest difference is review sentiment: RPN at 100% against i48's 54%. RPN also leads on rating (4.7 vs 3.5) and monetization model (free vs paid). i48's advantage is ratings volume (196 vs 11). On price, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
RPN holds the better App Store score, 4.7 against 3.5. That said, the two scores are not equally well evidenced: i48 has 196 ratings behind it against 11, so its average is the more settled of the two. Written reviews point the same way: 54% of i48's written reviews are positive against 100% of RPN's.
i48 ships an update every 4 months, RPN every 7 months. The most recent releases landed on October 8, 2026 and October 4, 2026 respectively.
| Parameter | i48 | RPN |
|---|---|---|
| Price | Free | Free |
| Rating | 3.5 (196 ratings) | 4.7 (11 ratings) — better |
| Positive reviews | 54.2% of reviews | 100.0% of reviews — better |
| Number of ratings | 196 — better | 11 |
| Update frequency | Every 4 months — better | Every 7 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 | 12.0 |
| Further details — not scored | ||
| Size | 4 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Automagic Software Pty Ltd | CuVee Software |
Customer experience
i48
RPN
Bugs and requests
i48
Reported bugs
4 issues- Memory recovery prompt not working
- Cursor keys behaving erratically
- Equation solver locking up the app
- Keyboard issues on certain devices
Requested features
4 requests- Landscape mode support
- Improved display resolution and graphics
- Haptic feedback for button presses
- Ability to assign units to numbers
RPN
Not enough reviews yet to summarise bugs or requests.
In-app purchases
i48
No in-app purchases
RPN
No in-app purchases
