# 擎天柱Cloud vs 子衿听书

The clearest difference is in-app purchases: 擎天柱Cloud at none against 子衿听书's 2. 擎天柱Cloud also leads on iOS requirement (10.0 vs 16.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. 子衿听书 sells 2 in-app purchases, starting at $9.99 per year. 擎天柱Cloud asks for nothing beyond the download.

擎天柱Cloud ships an update every 4 weeks, 子衿听书 fortnightly. The most recent releases landed on October 27, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | 擎天柱Cloud | 子衿听书 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 weeks | **Fortnightly** |
| Size | 86 MB | 30 MB |
| Requires iOS | **10.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [vanke](https://appshunter.io/developer/1245066763) | [Guangzhou Feynman Information Technology Co., Ltd.](https://appshunter.io/developer/1444983702) |

## What reviewers say

### 擎天柱Cloud

[App page](https://appshunter.io/ios/app/cloud/id1531318812)

**Features:** Vision Pro support

**In-app purchases:** none


### 子衿听书

[App page](https://appshunter.io/ios/app/txtpdfepubai/id6752794227)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 包年畅听 | $9.99 | per year |
| 终身购买 | $29.99 | one-time |


## Frequently asked questions

### Is 擎天柱Cloud free?

擎天柱Cloud is free to download, with no in-app purchases.

### Is 子衿听书 free?

子衿听书 is free to download, with in-app purchases available.

### Do 擎天柱Cloud or 子衿听书 have ads?

Neither 擎天柱Cloud nor 子衿听书 shows ads.

### Which is updated more often, 擎天柱Cloud or 子衿听书?

擎天柱Cloud ships an update every 4 weeks, and 子衿听书 fortnightly. Most recently, 擎天柱Cloud was updated on October 27, 2026 and 子衿听书 on October 6, 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.*