# Notopium vs AcoustiCalc

The clearest difference is price: Notopium at Free against AcoustiCalc's $3.99. Notopium also leads on iOS requirement (15.0 vs 17). AcoustiCalc's advantage is update cadence (daily vs every 4 months). On ads, in-app purchases and device support there is nothing between them.

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

Notopium ships an update every 4 months, AcoustiCalc daily. The most recent releases landed on October 28, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Notopium | AcoustiCalc |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Daily** |
| Size | 45 MB | 43 MB |
| Requires iOS | **15.0** | 17 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Meisam Yousefzadeh](https://appshunter.io/developer/1854807801) | [TRIMECH Dhaker](https://appshunter.io/developer/1832697893) |

## What reviewers say

### Notopium

[App page](https://appshunter.io/ios/app/notopium/id6759302623)

**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 Notopium free?

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

### Is AcoustiCalc free?

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

### Do Notopium or AcoustiCalc have ads?

Neither Notopium nor AcoustiCalc shows ads.

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

Notopium ships an update every 4 months, and AcoustiCalc daily. Most recently, Notopium was updated on October 28, 2026 and AcoustiCalc on October 24, 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.*