# SideBooks vs 読書尚友

The clearest difference is rating: SideBooks at 4.6 against 読書尚友's 4.0. SideBooks also leads on ads (none vs shown) and ratings volume (97 vs 1). On price, update cadence, in-app purchases and monetization model there is nothing between them.

Both are free to download. SideBooks sells 1 one-off in-app purchase and 読書尚友 sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

SideBooks holds the better App Store score, 4.6 against 4.0. That said, the two scores are not equally well evidenced: SideBooks has 97 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 74% of SideBooks's written reviews are positive against 50% of 読書尚友's.

SideBooks ships an update every 9 days, 読書尚友 every 2 weeks. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | SideBooks | 読書尚友 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (97 ratings)](https://appshunter.io/ios/app/sidebooks/id409777225/reviews)** | [4.0 (1 ratings)](https://appshunter.io/ios/app/id1579254502/reviews) |
| Number of ratings | **97** | 1 |
| Positive reviews | **73.7% of reviews** | 50.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 9 days** | Every 2 weeks |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 33 MB | 45 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Tatsumi-system Co., Ltd.](https://appshunter.io/developer/409777230) | [hishida](https://appshunter.io/developer/314082596) |

## What reviewers say

### SideBooks

[App page](https://appshunter.io/ios/app/sidebooks/id409777225)

This app offers a high-performance PDF and comic viewer with realistic paper-turning animations. It supports various viewing directions, enhanced bookshelf management, and secure password protection for your documents. Easily import files from multiple sources and enjoy a customizable reading experience.

**Highlights:** Realistic paper curl animation, Multiple viewing directions, Enhanced bookshelf management, Password protection, Dropbox and iTunes file import, Supports PDF, ZIP, CBZ, RAR, CBR

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Thema extension Add-On | $0.99 | one-time |

**What reviewers like**

- 🚀 Smooth page turning
- 📚 Great for reading comics and manga
- 🗂️ Excellent folder organization
- 🔍 Useful search and table of contents features
- 💻 Seamless Dropbox integration

**What reviewers complain about**

- 🐛 Crashes when loading large files
- 🚫 Limited file format support (no CBZ/CBR)
- 🔍 Difficult to find and delete books
- 🔒 Requires Dropbox access, no local file support
- 🔍 Small thumbnail size makes it hard to browse

**Reported bugs**

- Crashes when opening certain PDF files
- Corrupted files cause repeated crashes
- Dropbox integration issues on some devices

**Requested features**

- Add support for ePub and other popular formats
- Implement iCloud/Google Drive integration
- Allow manual rearrangement of bookshelf
- Add dark mode and customizable background options
- Improve bookmark and annotation features


### 読書尚友

[App page](https://appshunter.io/ios/app/id1579254502)

This app is a Japanese vertical text viewer for iOS, offering access to over 10,000 works from Aozora Bunko and supporting local files. It handles various formats and provides customization options for a comfortable reading experience.

**Highlights:** Supports various file formats (text, HTML, PDF, ePub, images, etc.), Automatic character code detection, Browse Aozora Bunko by author, title, genre, and ranking, Download books directly from Aozora Bunko, Customizable font, size, background, and page direction, In-app search and bookmarking

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 広告削除 | $1.99 | one-time |


## Frequently asked questions

### Is SideBooks free?

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

### Is 読書尚友 free?

読書尚友 is free to download, with in-app purchases available.

### Which has better reviews, SideBooks or 読書尚友?

SideBooks is rated higher. SideBooks averages 4.6 out of 5 from 97 ratings, while 読書尚友 averages 4.0 from 1 ratings.

### Do SideBooks or 読書尚友 have ads?

読書尚友 shows ads; SideBooks does not.

### Which is updated more often, SideBooks or 読書尚友?

SideBooks ships an update every 9 days, and 読書尚友 every 2 weeks. Most recently, SideBooks was updated on October 29, 2026 and 読書尚友 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.*