# SODUku vs Modstack

The clearest difference is in-app purchases: SODUku at none against Modstack's 1. Modstack's advantage is ads (none vs shown) and update cadence (every 8 days vs every 5 weeks). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Modstack sells 1 one-off in-app purchase. SODUku asks for nothing beyond the download.

SODUku ships an update every 5 weeks, Modstack every 8 days. The most recent releases landed on October 15, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | SODUku | Modstack |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/soduku-classic-sudoku-puzzle/id1510799463/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 5 weeks | **Every 8 days** |
| Monetization | Ad-supported | — |
| Size | 53 MB | 30 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nguyen Thanh Nam](https://appshunter.io/developer/1074606030) | [NovoBuild LLC](https://appshunter.io/developer/1784126512) |

## What reviewers say

### SODUku

[App page](https://appshunter.io/ios/app/soduku-classic-sudoku-puzzle/id1510799463)

Engage your mind with a classic Sudoku puzzle game offering thousands of challenges across four difficulty levels. Enjoy a relaxing, ad-supported experience with helpful hints and no time limits. Track your progress and customize your gameplay with different themes and sound options.

**Highlights:** Thousands of Sudoku puzzles, Four difficulty levels, Daily new puzzles, Free hints, No time limit, Offline play, Progress tracking

**Features:** macOS Compatibility

**In-app purchases:** none


### Modstack

[App page](https://appshunter.io/ios/app/modstack-programming-puzzle/id6803866356)

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Full Modstack | $3.99 | one-time |


## Frequently asked questions

### Is SODUku free?

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

### Is Modstack free?

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

### Do SODUku or Modstack have ads?

SODUku shows ads; Modstack does not.

### Which is updated more often, SODUku or Modstack?

SODUku ships an update every 5 weeks, and Modstack every 8 days. Most recently, SODUku was updated on October 15, 2026 and Modstack on October 10, 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.*