# Rule Book UBTZ vs DjVu Reader & Viewer

The clearest difference is in-app purchases: Rule Book UBTZ at none against DjVu Reader & Viewer's 2. Rule Book UBTZ also leads on iOS requirement (8.0 vs 16.2). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. DjVu Reader & Viewer sells 2 in-app purchases, starting at $2.99 per 7 days. Rule Book UBTZ asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on November 2, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | Rule Book UBTZ | DjVu Reader & Viewer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.2 (76 ratings)](https://appshunter.io/ios/app/djvu-reader-and-viewer/id6746808694/reviews)** |
| Number of ratings | — | **76** |
| Positive reviews | — | 25.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | Every 4 months |
| Monetization | — | Free with in-app purchases |
| Size | 27 MB | 35 MB |
| Requires iOS | **8.0** | 16.2 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [veritech](https://appshunter.io/developer/1044574972) | [Yassir Hrout](https://appshunter.io/developer/1813458400) |

## What reviewers say

### Rule Book UBTZ

[App page](https://appshunter.io/ios/app/rule-book-ubtz/id1125251709)

**In-app purchases:** none


### DjVu Reader & Viewer

[App page](https://appshunter.io/ios/app/djvu-reader-and-viewer/id6746808694)

This app offers a modern and elegant way to read DjVu documents on iOS devices. It features high-quality rendering, a smart document tracking system, and a clean interface optimized for technical and academic material.

**Highlights:** High-quality DjVu rendering, Smart document tracking, Clean, intuitive interface, Dark/White mode options, Powerful search capabilities, Optimized performance for large documents

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Plan | $2.99 | per 7 days |
| Lifetime Plan | $5.99 | one-time |


## Frequently asked questions

### Is Rule Book UBTZ free?

Rule Book UBTZ is free to download, with no in-app purchases.

### Is DjVu Reader & Viewer free?

DjVu Reader & Viewer is free to download, with in-app purchases available.

### Do Rule Book UBTZ or DjVu Reader & Viewer have ads?

Neither Rule Book UBTZ nor DjVu Reader & Viewer shows ads.

### Which is updated more often, Rule Book UBTZ or DjVu Reader & Viewer?

Rule Book UBTZ ships an update every 4 months, and DjVu Reader & Viewer every 4 months. Most recently, Rule Book UBTZ was updated on November 2, 2026 and DjVu Reader & Viewer on November 8, 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.*