# Mathrax vs Index Sums

The clearest difference is in-app purchases: Index Sums at none against Mathrax's 1. Index Sums also leads on ads (none vs shown) and update cadence (every 3 weeks vs every 6 months). On price, rating, review sentiment and device support there is nothing between them.

Both are free to download. Mathrax sells 1 one-off in-app purchase. Index Sums asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for Mathrax against 5.0 for Index Sums. Both are backed by a comparable volume of ratings — 1 and 4 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Mathrax ships an update every 6 months, Index Sums every 3 weeks. The most recent releases landed on November 1, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Mathrax | Index Sums |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/mathrax-sudoku-and-maths/id645221113/reviews) | [5.0 (4 ratings)](https://appshunter.io/ios/app/index-sums/id6745894447/reviews) |
| Number of ratings | 1 | **4** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 6 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 12 MB | 25 MB |
| Requires iOS | **17.0** | 17.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Stanley Lam](https://appshunter.io/developer/453164363) | [ZORIX LLC](https://appshunter.io/developer/1814371874) |

## What reviewers say

### Mathrax

[App page](https://appshunter.io/ios/app/mathrax-sudoku-and-maths/id645221113)

This logic puzzle game challenges you to fill grids with numbers based on specific mathematical and parity rules. It offers a variety of board sizes, difficulty levels, and hundreds of puzzles with features like automatic error highlighting and time tracking.

**Highlights:** Number placement logic puzzles, Mathematical operation constraints, Parity (even/odd) rules, Multiple board sizes and difficulty levels, Hundreds of unique levels, Automatic error highlighting, Autosave functionality

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade to Full Version | $0.99 | one-time |


### Index Sums

[App page](https://appshunter.io/ios/app/index-sums/id6745894447)

Engage your mind with a Japanese number logic puzzle. Fill grids based on row and column sums, using pure logic to reveal hidden patterns. Offers multiple difficulty levels and daily challenges for continuous mental stimulation.

**Highlights:** Row and column sum logic puzzles, Multiple difficulty levels, Daily challenges, Progress tracking and statistics, Offline play, Customizable themes, Haptic feedback

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Mathrax free?

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

### Is Index Sums free?

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

### Which has better reviews, Mathrax or Index Sums?

Mathrax and Index Sums are both rated 5.0 out of 5 on the App Store, from 1 and 4 ratings respectively.

### Do Mathrax or Index Sums have ads?

Mathrax shows ads; Index Sums does not.

### Which is updated more often, Mathrax or Index Sums?

Mathrax ships an update every 6 months, and Index Sums every 3 weeks. Most recently, Mathrax was updated on November 1, 2026 and Index Sums on October 30, 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.*