# Book.self vs Underlined

The clearest difference is in-app purchases: Book.self at none against Underlined's 2. Book.self also leads on update cadence (every 4 days vs fortnightly). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Underlined sells 2 in-app purchases, starting at $2.99 per month. Book.self asks for nothing beyond the download.

Book.self ships an update every 4 days, Underlined fortnightly. The most recent releases landed on October 25, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Book.self | Underlined |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Fortnightly |
| Size | 3 MB | 24 MB |
| Requires iOS | **17.6** | 18.0 |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Ana Luisa Luy da Silva](https://appshunter.io/developer/1830886845) | [Mert Arman](https://appshunter.io/developer/6795348333) |

## What reviewers say

### Book.self

[App page](https://appshunter.io/ios/app/bookself-book-quotes-and-notes/id6756063289)

**Features:** macOS Compatibility

**In-app purchases:** none


### Underlined

[App page](https://appshunter.io/ios/app/underlined-bookshelf-tracker/id6805132642)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Underlined - Monthly | $2.99 | per month |
| Underlined - Yearly | $19.99 | per year |


## Frequently asked questions

### Is Book.self free?

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

### Is Underlined free?

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

### Do Book.self or Underlined have ads?

Neither Book.self nor Underlined shows ads.

### Which is updated more often, Book.self or Underlined?

Book.self ships an update every 4 days, and Underlined fortnightly. Most recently, Book.self was updated on October 25, 2026 and Underlined on October 31, 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.*