# ISBN vs Fable Frog

The clearest difference is in-app purchases: ISBN at none against Fable Frog's 2. ISBN also leads on iOS requirement (14.0 vs 17.0). Fable Frog's advantage is ads (none vs shown) and update cadence (weekly vs every 4 months). On price and device support there is nothing between them.

Both are free to download. Fable Frog sells 2 in-app purchases, starting at $8.00 per year. ISBN asks for nothing beyond the download.

ISBN ships an update every 4 months, Fable Frog weekly. The most recent releases landed on October 19, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | ISBN | Fable Frog |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.3 (3 ratings)](https://appshunter.io/ios/app/fable-frog/id6760953386/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | — | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 4 months | **Weekly** |
| Monetization | — | Free with in-app purchases |
| Size | 16 MB | 33 MB |
| Requires iOS | **14.0** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [剑秋 肖](https://appshunter.io/developer/806037264) | [Paul DeVito](https://appshunter.io/developer/1886989873) |

## What reviewers say

### ISBN

[App page](https://appshunter.io/ios/app/isbn/id6449743934)

**Features:** macOS Compatibility

**In-app purchases:** none


### Fable Frog

[App page](https://appshunter.io/ios/app/fable-frog/id6760953386)

This app offers a premium listening experience for your self-hosted audiobooks. Enjoy advanced playback controls, library management, offline downloads, and detailed listening statistics. It's designed with accessibility and privacy in mind, connecting seamlessly to your Audiobookshelf server.

**Highlights:** Variable speed and volume boost, Sleep timer with shake to extend, Chapter navigation with durations, Bookmarks with notes, Per-book playback settings, Offline downloads with smart management, Listening statistics and charts, CarPlay and widget support

**Features:** macOS Compatibility, Family Sharing, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Annual | $8.00 | per year |
| Premium Lifetime | $12.00 | one-time |


## Frequently asked questions

### Is ISBN free?

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

### Is Fable Frog free?

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

### Do ISBN or Fable Frog have ads?

ISBN shows ads; Fable Frog does not.

### Which is updated more often, ISBN or Fable Frog?

ISBN ships an update every 4 months, and Fable Frog weekly. Most recently, ISBN was updated on October 19, 2026 and Fable Frog on October 15, 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.*