Calccis vs HP
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Calccis
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Calccis is a reverse polish notation (RPN) calculator. It supports basic arithmetic, trigonometrical, logarithm and exponent calculations for real, fractional, and complex numbers. Degrees and radians can be used for trigonometrical functions. You can perform matrix calculations, too. There is an undo stack, which supports undoing and redoing the 100 latest operations. Calccis does not copy or mimic any existing physical calculators. However, the operation of the stack has been influenced by how the stack works in the 1990s Hewlett-Packard HP-48 family of calculators.
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
Calccis and HP are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
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.
Calccis ships an update every 3 weeks, HP every 11 days. The most recent releases landed on September 12, 2026 and October 8, 2026 respectively.
| Parameter | Calccis | HP |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (5 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | — | 5 — better |
| Update frequency | Every 3 weeks | Every 11 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 17.6 | 17.2 — better |
| Further details — not scored | ||
| Size | 1 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Jukka Aittola | Enrique Haro |
In-app purchases
Calccis
No in-app purchases
HP
No in-app purchases









