# Sourdline vs Book Flip Notes

The clearest difference is in-app purchases: Sourdline at none against Book Flip Notes's 1. Sourdline also leads on update cadence (every 2 days vs fortnightly) and iOS requirement (15.1 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Book Flip Notes sells 1 one-off in-app purchase. Sourdline asks for nothing beyond the download.

Sourdline ships an update every 2 days, Book Flip Notes fortnightly. The most recent releases landed on August 13, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | Sourdline | Book Flip Notes |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Fortnightly |
| Size | 52 MB | 64 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [SOURDLINE DEVELOPPEMENT](https://appshunter.io/developer/1887293373) | [lecoo](https://appshunter.io/developer/1630534948) |

## What reviewers say

### Sourdline

[App page](https://appshunter.io/ios/app/sourdline/id6761013175)

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

**In-app purchases:** none


### Book Flip Notes

[App page](https://appshunter.io/ios/app/book-flip-notes/id6782423238)

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Pro | $0.99 | one-time |


## Frequently asked questions

### Is Sourdline free?

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

### Is Book Flip Notes free?

Book Flip Notes is free to download, with in-app purchases available.

### Do Sourdline or Book Flip Notes have ads?

Neither Sourdline nor Book Flip Notes shows ads.

### Which is updated more often, Sourdline or Book Flip Notes?

Sourdline ships an update every 2 days, and Book Flip Notes fortnightly. Most recently, Sourdline was updated on August 13, 2026 and Book Flip Notes on September 25, 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.*