bcRPN vs HP
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
bcRPN
This utility app functions as a Reverse Polish Notation calculator. It handles complex numbers and utilizes extended precision for all calculations, offering an unlimited stack depth and an undo feature for up to 10 operations.
- Reverse Polish Notation (RPN) input
- Complex number calculations
- Extended precision math
- Unlimited stack depth
- Undo functionality (up to 10 operations)
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This is a RPN (Reverse Polish Notation) Calculator. It supports complex numbers and uses extended precision math for all operations. The stack depth is unlimited. In case a mistake was made, up to 10 operations can be undone. RPN calculators work by entering the numbers on the stack first, then selecting the operation. For example to add 3 + 4, press: 3 Enter 4 +
HP
Emulates classic Hewlett Packard RPN scientific calculators from the 1970s. Experience the original HP-35, HP-45, and HP-21 models on your iPhone.
- RPN calculator emulation
- HP-35 model
- HP-45 model
- HP-21 model
- Classic scientific calculator interface
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The classic Hewlett Packard RPN (Reverse Polish Notation) calculators. - HP-35, HP-45. First pocket scientific calculators (1972). - HP-21. 2nd gen of the HP-35 (1975)
Screenshots
Verdict
The clearest difference is update cadence: HP at every 11 days against bcRPN's every 22 months. HP also leads on review sentiment (100% vs 80%) and rating (5.0 vs 4.8). bcRPN's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.2). On price, ratings volume, 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.
HP holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 4 and 5 respectively. Written reviews point the same way: 80% of bcRPN's written reviews are positive against 100% of HP's.
bcRPN ships an update every 22 months, HP every 11 days. The most recent releases landed on September 19, 2026 and September 21, 2026 respectively.
| Parameter | bcRPN | HP |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (4 ratings) | 5.0 (5 ratings) — better |
| Positive reviews | 80.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 4 | 5 — better |
| Update frequency | Every 22 months | Every 11 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 17.2 |
| Further details — not scored | ||
| Size | 0 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Paul Wilkins | Enrique Haro |
Customer experience
bcRPN
HP
In-app purchases
bcRPN
No in-app purchases
HP
No in-app purchases
