# Castly vs Kinder

The clearest difference is in-app purchases: Kinder at none against Castly's 2. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Castly sells 2 in-app purchases, starting at $9.99 per month. Kinder asks for nothing beyond the download.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 31, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Castly | Kinder |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Weekly | Weekly |
| Size | 29 MB | 7 MB |
| Requires iOS | **18.0** | 18.6 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [SlothEase](https://appshunter.io/developer/1816632091) | [功亮 张](https://appshunter.io/developer/1826484363) |

## What reviewers say

### Castly

[App page](https://appshunter.io/ios/app/castly-ai-audiobook-reader/id6768542554)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Castly Pro Monthly | $9.99 | per month |
| Castly Pro Annual | $49.99 | per year |


### Kinder

[App page](https://appshunter.io/ios/app/kinder-ebook-reader/id6779840110)

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

**In-app purchases:** none


## Frequently asked questions

### Is Castly free?

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

### Is Kinder free?

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

### Do Castly or Kinder have ads?

Neither Castly nor Kinder shows ads.

### Which is updated more often, Castly or Kinder?

Castly ships an update weekly, and Kinder weekly. Most recently, Castly was updated on October 31, 2026 and Kinder on October 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.*