# Karatu vs Stacks

The clearest difference is in-app purchases: Karatu at none against Stacks's 4. Karatu also leads on update cadence (daily vs every 5 days). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Stacks sells 4 in-app purchases, starting at $2.99 per month. Karatu asks for nothing beyond the download.

Karatu ships an update daily, Stacks every 5 days. The most recent releases landed on October 25, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | Karatu | Stacks |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/stacks-book-scanner-and-library/id6778984902/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Daily** | Every 5 days |
| Monetization | — | Freemium |
| Size | 2 MB | 19 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 17+ | 4+ |
| Developer | [Umar Rufai](https://appshunter.io/developer/1895570634) | [Zenmonkeys Digital LLC](https://appshunter.io/developer/1868802546) |

## What reviewers say

### Karatu

[App page](https://appshunter.io/ios/app/karatu/id6765975970)

**Features:** macOS Compatibility

**In-app purchases:** none


### Stacks

[App page](https://appshunter.io/ios/app/stacks-book-scanner-and-library/id6778984902)

Digitally catalog your physical book collection by scanning shelves or barcodes. Track reading progress, discover new books based on your taste, and manage your library with visual shelf displays and smart sorting. Offers insights into your reading habits and a wishlist feature.

**Highlights:** Shelf scanning for bulk book cataloging, Barcode scanning with auto-fill, Import/export from Goodreads/StoryGraph, Visual shelf and spine display, Reading progress tracking, Book scouting and wishlist building, Personalized reading recommendations

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $2.99 | per month |
| Pro Yearly | $19.99 | per year |
| 3 Scans | $0.99 | one-time |
| 15 Scans | $3.99 | one-time |


## Frequently asked questions

### Is Karatu free?

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

### Is Stacks free?

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

### Do Karatu or Stacks have ads?

Neither Karatu nor Stacks shows ads.

### Which is updated more often, Karatu or Stacks?

Karatu ships an update daily, and Stacks every 5 days. Most recently, Karatu was updated on October 25, 2026 and Stacks on November 1, 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.*