# 书童AR互动科普 vs 知了单词书

The clearest difference is in-app purchases: 书童AR互动科普 at none against 知了单词书's 1. 书童AR互动科普 also leads on iOS requirement (10.0 vs 12.0). 知了单词书's advantage is update cadence (every 5 days vs every 6 weeks). On price, ads and device support there is nothing between them.

Both are free to download. 知了单词书 sells 1 one-off in-app purchase. 书童AR互动科普 asks for nothing beyond the download.

书童AR互动科普 ships an update every 6 weeks, 知了单词书 every 5 days. The most recent releases landed on September 6, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | 书童AR互动科普 | 知了单词书 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 5 days** |
| Size | 2.7 GB | 63 MB |
| Requires iOS | **10.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [训龙 何](https://appshunter.io/developer/878033547) | [重庆知竣文化传媒有限公司](https://appshunter.io/developer/1814794912) |

## What reviewers say

### 书童AR互动科普

[App page](https://appshunter.io/ios/app/ar/id1239255493)

**Features:** macOS Compatibility

**In-app purchases:** none


### 知了单词书

[App page](https://appshunter.io/ios/app/id6746037035)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 知了1年会员 | $39.99 | one-time |


## Frequently asked questions

### Is 书童AR互动科普 free?

书童AR互动科普 is free to download, with no in-app purchases.

### Is 知了单词书 free?

知了单词书 is free to download, with in-app purchases available.

### Do 书童AR互动科普 or 知了单词书 have ads?

Neither 书童AR互动科普 nor 知了单词书 shows ads.

### Which is updated more often, 书童AR互动科普 or 知了单词书?

书童AR互动科普 ships an update every 6 weeks, and 知了单词书 every 5 days. Most recently, 书童AR互动科普 was updated on September 6, 2026 and 知了单词书 on September 19, 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.*