# Proofreader AI Grammar Checker vs 370 Interlocken

The clearest difference is in-app purchases: 370 Interlocken at none against Proofreader AI Grammar Checker's 11. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Proofreader AI Grammar Checker sells 8 in-app purchases, starting at $4.99 per month. 370 Interlocken asks for nothing beyond the download.

Proofreader AI Grammar Checker ships an update fortnightly, 370 Interlocken every 2 weeks. The most recent releases landed on October 17, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Proofreader AI Grammar Checker | 370 Interlocken |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (3.3K ratings)](https://appshunter.io/ios/app/proofreader-ai-grammar-checker/id1494119626/reviews)** | — |
| Number of ratings | **3.3K** | — |
| Positive reviews | 64.7% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 2 weeks |
| Monetization | Freemium | — |
| Size | 59 MB | 99 MB |
| Requires iOS | 16.6 | **15.6** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [BlueSoar SL](https://appshunter.io/developer/1493410779) | [Columbia Center](https://appshunter.io/developer/1470151383) |

## What reviewers say

### Proofreader AI Grammar Checker

[App page](https://appshunter.io/ios/app/proofreader-ai-grammar-checker/id1494119626)

Enhance your writing with an AI-powered keyboard and assistant. Correct grammar, spelling, and punctuation, and improve clarity and style. Generate text, rewrite sentences, and expand your vocabulary anywhere you type.

**Highlights:** AI Keyboard with one-tap proofreading, Advanced grammar, spelling, and punctuation checker, AI rewriting and paraphrasing, Text generation and vocabulary enhancement, Style and clarity improvements, Translator and dictionary

**Features:** Vision Pro support

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Proofreader Pro | $4.99 | per month |
| Proofreader Pro | $9.99 | per month |
| Monthly Plan | $9.99 | per month |
| Proofreader Pro | $13.49 | per 3 months |
| Proofreader Pro | $24.99 | per 3 months |
| Proofreader Pro | $39.99 | per year |
| Proofreader Pro | $47.99 | per year |
| Proofreader Pro | $49.99 | per year |

**What reviewers like**

- 🚀 Helpful grammar and writing suggestions
- 👍 Easy to use
- 💡 Affordable alternative to Grammarly
- 👍 Explains why changes are suggested
- 💡 Useful for non-native English speakers

**What reviewers complain about**

- 🐛 Inconsistent performance, sometimes misses errors
- 🔍 Limited functionality in free version
- 🔍 Subscription required for full features
- 🐛 Issues with pasting text into other apps
- 🐛 Struggles with specialized/foreign names

**Reported bugs**

- Difficulty cancelling subscriptions
- Unexpected charges during free trials
- App crashes or freezes
- Incorrect grammar/spelling corrections

**Requested features**

- Keyboard integration for easier use
- More customization options
- Improved accuracy and consistency
- Desktop/browser extension version
- Better handling of creative/informal writing styles


### 370 Interlocken

[App page](https://appshunter.io/ios/app/370-interlocken/id6748962651)

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

**In-app purchases:** none


## Frequently asked questions

### Is Proofreader AI Grammar Checker free?

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

### Is 370 Interlocken free?

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

### Do Proofreader AI Grammar Checker or 370 Interlocken have ads?

Neither Proofreader AI Grammar Checker nor 370 Interlocken shows ads.

### Which is updated more often, Proofreader AI Grammar Checker or 370 Interlocken?

Proofreader AI Grammar Checker ships an update fortnightly, and 370 Interlocken every 2 weeks. Most recently, Proofreader AI Grammar Checker was updated on October 17, 2026 and 370 Interlocken on October 5, 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.*