# Knock, knock, knock! vs Biblio Library

The clearest difference is price: Biblio Library at Free against Knock, knock, knock!'s $2.99. Biblio Library also leads on update cadence (every 2 months vs every 48 months) and review sentiment (13% vs 0%). Knock, knock, knock!'s advantage is iOS requirement (9.3 vs 12.0). On ads, in-app purchases and device support there is nothing between them.

Biblio Library is free to download; Knock, knock, knock! costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Knock, knock, knock! ships an update every 48 months, Biblio Library every 2 months. The most recent releases landed on November 1, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Knock, knock, knock! | Biblio Library |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | — | **[3.0 (10 ratings)](https://appshunter.io/ios/app/biblio-library/id1286685079/reviews)** |
| Number of ratings | — | **10** |
| Positive reviews | 0.0% of reviews | **12.5% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 48 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Size | 121 MB | 35 MB |
| Requires iOS | **9.3** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Alfabeta](https://appshunter.io/developer/586381859) | [Axiellmedia AB](https://appshunter.io/developer/1286685078) |

## What reviewers say

### Knock, knock, knock!

[App page](https://appshunter.io/ios/app/knock-knock-knock/id586381856)

This interactive book app brings a classic children's story to life with engaging page-turning and the ability to record your own narration. It's designed for young children to enjoy a beloved tale in a new digital format.

**Highlights:** Interactive page turning, Recordable narration, Multiple language options, Classic children's story, Designed for toddlers

**In-app purchases:** none


### Biblio Library

[App page](https://appshunter.io/ios/app/biblio-library/id1286685079)

Access and enjoy your library's digital audiobooks and e-books in one convenient application. Stream or download titles for offline listening and reading, making literature accessible anywhere.

**Highlights:** Borrow digital books, Read and listen to literature, Offline access, Explore top lists and categories, Search for favorite titles, Pause playback for calls

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Knock, knock, knock! free?

Knock, knock, knock! costs $2.99, with no in-app purchases.

### Is Biblio Library free?

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

### Do Knock, knock, knock! or Biblio Library have ads?

Neither Knock, knock, knock! nor Biblio Library shows ads.

### Which is updated more often, Knock, knock, knock! or Biblio Library?

Knock, knock, knock! ships an update every 48 months, and Biblio Library every 2 months. Most recently, Knock, knock, knock! was updated on November 1, 2026 and Biblio Library on October 6, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*