# Cereby vs (Open Source) Mental Math

The clearest difference is in-app purchases: (Open Source) Mental Math at none against Cereby's 6. Cereby's advantage is update cadence (every 3 days vs every 5 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Cereby sells 6 in-app purchases, starting at $9.99 per month. (Open Source) Mental Math asks for nothing beyond the download.

Cereby ships an update every 3 days, (Open Source) Mental Math every 5 weeks. The most recent releases landed on October 21, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Cereby | (Open Source) Mental Math |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[3.0 (2 ratings)](https://appshunter.io/ios/app/open-source-mental-math/id6788418444/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 5 weeks |
| Monetization | — | Free |
| Size | 10 MB | 41 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Lovinson Dieujuste](https://appshunter.io/developer/6780308934) | [AHMET EMRE DEDELER](https://appshunter.io/developer/1870913629) |

## What reviewers say

### Cereby

[App page](https://appshunter.io/ios/app/cereby-ai-notes-and-flashcards/id6780308932)

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cereby Lite (Monthly) | $9.99 | per month |
| Cereby Pro (Monthly) | $16.99 | per month |
| Cereby Premium (Monthly) | $26.99 | per month |
| Cereby Lite (Annual) | $95.99 | per year |
| Cereby Pro (Annual) | $155.99 | per year |
| Cereby Premium (Annual) | $250.00 | per year |


### (Open Source) Mental Math

[App page](https://appshunter.io/ios/app/open-source-mental-math/id6788418444)

This application offers a free, open-source platform for practicing mental arithmetic. It features timed tests, custom drills, and a comprehensive library of mental math tricks. All content is available offline without ads or paywalls.

**Highlights:** Timed arithmetic tests, Customizable drills, Mental math tricks library, Offline progress tracking, Multiple operation types, Fast session interface

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

**In-app purchases:** none


## Frequently asked questions

### Is Cereby free?

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

### Is (Open Source) Mental Math free?

(Open Source) Mental Math is free to download, with no in-app purchases.

### Do Cereby or (Open Source) Mental Math have ads?

Neither Cereby nor (Open Source) Mental Math shows ads.

### Which is updated more often, Cereby or (Open Source) Mental Math?

Cereby ships an update every 3 days, and (Open Source) Mental Math every 5 weeks. Most recently, Cereby was updated on October 21, 2026 and (Open Source) Mental Math on October 6, 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.*