# BiLibre DjVu and PDF Reader vs Shor's algorithm

The clearest difference is price: Shor's algorithm at Free against BiLibre DjVu and PDF Reader's $1.99. BiLibre DjVu and PDF Reader's advantage is in-app purchases (none vs 3) and update cadence (every 10 days vs every 6 months). On ads and device support there is nothing between them.

Shor's algorithm is free to download; BiLibre DjVu and PDF Reader costs $1.99 up front. Shor's algorithm sells 3 one-off in-app purchases. BiLibre DjVu and PDF Reader asks for nothing beyond the download.

BiLibre DjVu and PDF Reader ships an update every 10 days, Shor's algorithm every 6 months. The most recent releases landed on October 24, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | BiLibre DjVu and PDF Reader | Shor's algorithm |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[4.3 (103 ratings)](https://appshunter.io/ios/app/bilibre-djvu-and-pdf-reader/id1230039040/reviews)** | — |
| Number of ratings | **103** | — |
| Positive reviews | 41.1% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 6 months |
| Monetization | Paid | — |
| Best chart rank | **#190** | — |
| Size | 57 MB | 7 MB |
| Requires iOS | **10.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Konstantin Bukreev](https://appshunter.io/developer/547576207) | [Sungjun Kim](https://appshunter.io/developer/1602461985) |

## What reviewers say

### BiLibre DjVu and PDF Reader

[App page](https://appshunter.io/ios/app/bilibre-djvu-and-pdf-reader/id1230039040)

**Currently charting:** #190 Top Paid · Education (US App Store)

Read and organize technical, scientific, and educational literature in DjVu and PDF formats. Features include customizable reading modes, powerful annotation tools, a built-in summary editor, and advanced DjVu processing. Manage your library with smart cataloging and metadata editing.

**Highlights:** Customizable reading modes, Annotation and drawing tools, Summary editor with Markdown, DjVu text recognition, Full text searching, Library cataloging and metadata editing, Cloud synchronization

**Features:** macOS Compatibility

**In-app purchases:** none


### Shor's algorithm

[App page](https://appshunter.io/ios/app/shors-algorithm/id6472044082)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| coffee | $0.99 | one-time |
| latte | $4.99 | one-time |
| whopper set | $9.99 | one-time |


## Frequently asked questions

### Is BiLibre DjVu and PDF Reader free?

BiLibre DjVu and PDF Reader costs $1.99, with no in-app purchases.

### Is Shor's algorithm free?

Shor's algorithm is free to download, with in-app purchases available.

### Do BiLibre DjVu and PDF Reader or Shor's algorithm have ads?

Neither BiLibre DjVu and PDF Reader nor Shor's algorithm shows ads.

### Which is updated more often, BiLibre DjVu and PDF Reader or Shor's algorithm?

BiLibre DjVu and PDF Reader ships an update every 10 days, and Shor's algorithm every 6 months. Most recently, BiLibre DjVu and PDF Reader was updated on October 24, 2026 and Shor's algorithm 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.*