# HP vs AcoustiCalc

The clearest difference is price: HP at Free against AcoustiCalc's $3.99. AcoustiCalc's advantage is update cadence (daily vs every 11 days). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

HP is free to download; AcoustiCalc costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

HP ships an update every 11 days, AcoustiCalc daily. Both last shipped on October 8, 2026.

## The numbers

| Metric | HP | AcoustiCalc |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | **[5.0 (5 ratings)](https://appshunter.io/ios/app/hp-35/id6738010641/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 11 days | **Daily** |
| Monetization | Free | — |
| Size | 2 MB | 43 MB |
| Requires iOS | 17.2 | **17** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Enrique Haro](https://appshunter.io/developer/1778874870) | [TRIMECH Dhaker](https://appshunter.io/developer/1832697893) |

## What reviewers say

### HP

[App page](https://appshunter.io/ios/app/hp-35/id6738010641)

Emulates classic Hewlett Packard RPN scientific calculators from the 1970s. Experience the original HP-35, HP-45, and HP-21 models on your iPhone.

**Highlights:** RPN calculator emulation, HP-35 model, HP-45 model, HP-21 model, Classic scientific calculator interface

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### AcoustiCalc

[App page](https://appshunter.io/ios/app/acousticalc/id6764106645)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is HP free?

HP is free to download, with no in-app purchases.

### Is AcoustiCalc free?

AcoustiCalc costs $3.99, with no in-app purchases.

### Do HP or AcoustiCalc have ads?

Neither HP nor AcoustiCalc shows ads.

### Which is updated more often, HP or AcoustiCalc?

HP ships an update every 11 days, and AcoustiCalc daily. Most recently, HP was updated on October 8, 2026 and AcoustiCalc on October 8, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*