# AI Vocabulary Book (Multiling vs CheckBoostAudio

The clearest difference is in-app purchases: CheckBoostAudio at none against AI Vocabulary Book (Multiling's 1. CheckBoostAudio also leads on ads (none vs shown) and update cadence (every 3 days vs every 2 weeks). On price and device support there is nothing between them.

Both are free to download. AI Vocabulary Book (Multiling sells 1 in-app purchase, starting at $0.99 per month. CheckBoostAudio asks for nothing beyond the download.

AI Vocabulary Book (Multiling ships an update every 2 weeks, CheckBoostAudio every 3 days. The most recent releases landed on November 11, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | AI Vocabulary Book (Multiling | CheckBoostAudio |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 weeks | **Every 3 days** |
| Size | 12 MB | 32 MB |
| Requires iOS | 16.0 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Kazuaki Takahashi](https://appshunter.io/developer/1691521543) | [Masatomo Fukuda](https://appshunter.io/developer/1599921920) |

## What reviewers say

### AI Vocabulary Book (Multiling

[App page](https://appshunter.io/ios/app/ai-vocabulary-book-multiling/id6462388172)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| AI Vocabulary Book PRO Edition | $0.99 | per month |


### CheckBoostAudio

[App page](https://appshunter.io/ios/app/checkboostaudio/id6740433605)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is AI Vocabulary Book (Multiling free?

AI Vocabulary Book (Multiling is free to download, with in-app purchases available.

### Is CheckBoostAudio free?

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

### Do AI Vocabulary Book (Multiling or CheckBoostAudio have ads?

AI Vocabulary Book (Multiling shows ads; CheckBoostAudio does not.

### Which is updated more often, AI Vocabulary Book (Multiling or CheckBoostAudio?

AI Vocabulary Book (Multiling ships an update every 2 weeks, and CheckBoostAudio every 3 days. Most recently, AI Vocabulary Book (Multiling was updated on November 11, 2026 and CheckBoostAudio on November 8, 2026.

---

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