# Plain850：核心英文 850詞 vs Kay Ogden

The clearest difference is in-app purchases: Plain850：核心英文 850詞 at none against Kay Ogden's 2. Plain850：核心英文 850詞 also leads on iOS requirement (13.0 vs 15.0). Kay Ogden's advantage is update cadence (every 2 days vs every 2 weeks). On price, ads and device support there is nothing between them.

Both are free to download. Kay Ogden sells 2 in-app purchases, starting at $0.99 per month. Plain850：核心英文 850詞 asks for nothing beyond the download.

Plain850：核心英文 850詞 ships an update every 2 weeks, Kay Ogden every 2 days. The most recent releases landed on September 9, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Plain850：核心英文 850詞 | Kay Ogden |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 2 days** |
| Size | 43 MB | 804 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Lok Wai](https://appshunter.io/developer/1895320924) | [小琦 王](https://appshunter.io/developer/1894109384) |

## What reviewers say

### Plain850：核心英文 850詞

[App page](https://appshunter.io/ios/app/plain850-850/id6776902920)

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

**In-app purchases:** none


### Kay Ogden

[App page](https://appshunter.io/ios/app/kay-ogden/id6800209525)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| AI Writing Monthly | $0.99 | per month |
| Kay Support | $1.99 | per month |


## Frequently asked questions

### Is Plain850：核心英文 850詞 free?

Plain850：核心英文 850詞 is free to download, with no in-app purchases.

### Is Kay Ogden free?

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

### Do Plain850：核心英文 850詞 or Kay Ogden have ads?

Neither Plain850：核心英文 850詞 nor Kay Ogden shows ads.

### Which is updated more often, Plain850：核心英文 850詞 or Kay Ogden?

Plain850：核心英文 850詞 ships an update every 2 weeks, and Kay Ogden every 2 days. Most recently, Plain850：核心英文 850詞 was updated on September 9, 2026 and Kay Ogden on September 8, 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.*