# Common Error vs Grammar AI Checker

The clearest difference is in-app purchases: Common Error at none against Grammar AI Checker's 3. Common Error also leads on iOS requirement (7.0 vs 16.6). Grammar AI Checker's advantage is update cadence (every 5 days vs every 35 months). On price, ads and device support there is nothing between them.

Both are free to download. Grammar AI Checker sells 3 in-app purchases, starting at $4.99 per 7 days. Common Error asks for nothing beyond the download.

Common Error ships an update every 35 months, Grammar AI Checker every 5 days. The most recent releases landed on September 17, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Common Error | Grammar AI Checker |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 35 months | **Every 5 days** |
| Size | 7 MB | 16 MB |
| Requires iOS | **7.0** | 16.6 |
| Devices | iPhone, iPod | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Le Thi Quynh Ny](https://appshunter.io/developer/1321764676) | [Muhammad Zubair](https://appshunter.io/developer/1802731328) |

## What reviewers say

### Common Error

[App page](https://appshunter.io/ios/app/common-error/id1224350614)

**Features:** macOS Compatibility

**In-app purchases:** none


### Grammar AI Checker

[App page](https://appshunter.io/ios/app/grammar-ai-checker-correctify/id6745131479)

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| AI Grammar Checker Weekly | $4.99 | per 7 days |
| AI Grammar Checker Monthly | $6.99 | per month |
| AI Grammar Checker Yearly | $19.99 | per year |


## Frequently asked questions

### Is Common Error free?

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

### Is Grammar AI Checker free?

Grammar AI Checker is free to download, with in-app purchases available.

### Do Common Error or Grammar AI Checker have ads?

Neither Common Error nor Grammar AI Checker shows ads.

### Which is updated more often, Common Error or Grammar AI Checker?

Common Error ships an update every 35 months, and Grammar AI Checker every 5 days. Most recently, Common Error was updated on September 17, 2026 and Grammar AI Checker on September 21, 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.*