# Zetamac Arithmetic Practice vs Kelma Immersion

The clearest difference is in-app purchases: Zetamac Arithmetic Practice at none against Kelma Immersion's 2. Zetamac Arithmetic Practice also leads on update cadence (daily vs every 5 weeks). Kelma Immersion's advantage is iOS requirement (15.1 vs 17.5). On price, ads and device support there is nothing between them.

Both are free to download. Kelma Immersion sells 2 in-app purchases, starting at $5.00 per month. Zetamac Arithmetic Practice asks for nothing beyond the download.

Zetamac Arithmetic Practice ships an update daily, Kelma Immersion every 5 weeks. The most recent releases landed on October 25, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Zetamac Arithmetic Practice | Kelma Immersion |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (19 ratings)](https://appshunter.io/ios/app/zetamac-arithmetic-practice/id6737153617/reviews)** | — |
| Number of ratings | **19** | — |
| Positive reviews | 83.3% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Daily** | Every 5 weeks |
| Monetization | Free | — |
| Size | 1 MB | 43 MB |
| Requires iOS | 17.5 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Joseph Ma](https://appshunter.io/developer/1774979062) | [Kelma Tech LLC](https://appshunter.io/developer/6800810886) |

## What reviewers say

### Zetamac Arithmetic Practice

[App page](https://appshunter.io/ios/app/zetamac-arithmetic-practice/id6737153617)

This app offers mental math practice tailored for quantitative finance professionals. It focuses on improving calculation speed and accuracy for complex numerical problems.

**Highlights:** Mental math practice, Quantitative finance focus, Calculation speed improvement, Accuracy enhancement, Numerical problem solving

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

**In-app purchases:** none


### Kelma Immersion

[App page](https://appshunter.io/ios/app/kelma-immersion/id6800810884)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Kelma Basic | $5.00 | per month |
| Kelma Pro | $10.00 | per month |


## Frequently asked questions

### Is Zetamac Arithmetic Practice free?

Zetamac Arithmetic Practice is free to download, with no in-app purchases.

### Is Kelma Immersion free?

Kelma Immersion is free to download, with in-app purchases available.

### Do Zetamac Arithmetic Practice or Kelma Immersion have ads?

Neither Zetamac Arithmetic Practice nor Kelma Immersion shows ads.

### Which is updated more often, Zetamac Arithmetic Practice or Kelma Immersion?

Zetamac Arithmetic Practice ships an update daily, and Kelma Immersion every 5 weeks. Most recently, Zetamac Arithmetic Practice was updated on October 25, 2026 and Kelma Immersion on October 17, 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.*