# Sudoku² vs PDF Watch Viewer

The clearest difference is review sentiment: Sudoku² at 81% against PDF Watch Viewer's 32%. Sudoku² also leads on device support (4 vs 2) and iOS requirement (12.0 vs 17.0). PDF Watch Viewer's advantage is rating (4.6 vs 3.9) and ads (none vs shown). On price, in-app purchases and monetization model there is nothing between them.

Both are free to download. Sudoku² sells 1 one-off in-app purchase and PDF Watch Viewer sells 9 in-app purchases, starting at $4.99 per 7 days. Whichever you choose, the download price is not the number that matters.

PDF Watch Viewer holds the better App Store score, 4.6 against 3.9. That said, the two scores are not equally well evidenced: PDF Watch Viewer has 397 ratings behind it against 10, so its average is the more settled of the two. Written reviews complicate that: 81% of Sudoku²'s written reviews are positive against 32% of PDF Watch Viewer's, so the app with the better star average is not the one people write more warmly about.

Sudoku² ships an update every 4 months, PDF Watch Viewer fortnightly. The most recent releases landed on October 23, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Sudoku² | PDF Watch Viewer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.9 (10 ratings)](https://appshunter.io/ios/app/sudoku/id959450517/reviews) | **[4.6 (397 ratings)](https://appshunter.io/ios/app/pdf-watch-viewer-wristdocs/id6745387064/reviews)** |
| Number of ratings | 10 | **397** |
| Positive reviews | **80.8% of reviews** | 31.9% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 4 months | **Fortnightly** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 6 MB | 84 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [春 李](https://appshunter.io/developer/525245233) | [ONNEX YAZILIM ANONIM SIRKETI](https://appshunter.io/developer/1856674142) |

## What reviewers say

### Sudoku²

[App page](https://appshunter.io/ios/app/sudoku/id959450517)

Engage with an endless supply of Sudoku puzzles, ranging from easy to challenging difficulty levels. Features include a distraction-free input pad, note-taking with color options, and customizable error checking. Unlock new levels by completing a single puzzle.

**Highlights:** Infinite Sudoku puzzles, Adjustable difficulty levels, Distraction-free input pad, Color-coded note-taking, Manual/automatic note-taking, Customizable error checking, Multiple highlight modes

**Features:** Apple Watch app, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Advertisement | $0.99 | one-time |


### PDF Watch Viewer

[App page](https://appshunter.io/ios/app/pdf-watch-viewer-wristdocs/id6745387064)

View PDF, Word, Excel, and text files directly on your Apple Watch. Easily navigate, zoom, and organize documents for quick access on the go. Syncs seamlessly with your iPhone for offline viewing.

**Highlights:** PDF, Word, Excel, Text file support, Zoom and page navigation, Favorites and collections, Seamless iPhone sync, Offline access, Image and notes support

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Subscription | $4.99 | per 7 days |
| Weekly Subscription | $6.99 | per 7 days |
| WristDocs Six Months Premium | $9.99 | per 6 months |
| Monthly Subscription | $9.99 | per month |
| 6-Month Premium | $14.99 | per 6 months |
| Annual Subscription | $19.99 | per year |
| Annual Subscription | $29.99 | per year |
| Lifetime Access | $29.99 | one-time |
| Lifetime Premium Access | $59.99 | one-time |


## Frequently asked questions

### Is Sudoku² free?

Sudoku² is free to download, with in-app purchases available.

### Is PDF Watch Viewer free?

PDF Watch Viewer is free to download, with in-app purchases available.

### Which has better reviews, Sudoku² or PDF Watch Viewer?

PDF Watch Viewer is rated higher. Sudoku² averages 3.9 out of 5 from 10 ratings, while PDF Watch Viewer averages 4.6 from 397 ratings.

### Do Sudoku² or PDF Watch Viewer have ads?

Sudoku² shows ads; PDF Watch Viewer does not.

### Which is updated more often, Sudoku² or PDF Watch Viewer?

Sudoku² ships an update every 4 months, and PDF Watch Viewer fortnightly. Most recently, Sudoku² was updated on October 23, 2026 and PDF Watch Viewer 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.*