# B737 MRG vs 737 Master Caution

The clearest difference is rating: B737 MRG at 4.9 against 737 Master Caution's 4.4. B737 MRG also leads on ratings volume (292 vs 7) and update cadence (monthly vs every 3 months). 737 Master Caution's advantage is in-app purchases (none vs 1) and iOS requirement (13.0 vs 16.6). On price, ads and device support there is nothing between them.

Both are free to download. B737 MRG sells 1 in-app purchase, starting at $9.99 per year. 737 Master Caution asks for nothing beyond the download.

B737 MRG holds the better App Store score, 4.9 against 4.4. That said, the two scores are not equally well evidenced: B737 MRG has 292 ratings behind it against 7, so its average is the more settled of the two.

B737 MRG ships an update monthly, 737 Master Caution every 3 months. The most recent releases landed on September 26, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | B737 MRG | 737 Master Caution |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (292 ratings)](https://appshunter.io/ios/app/b737-mrg/id481163421/reviews)** | [4.4 (7 ratings)](https://appshunter.io/ios/app/737-master-caution/id6455042070/reviews) |
| Number of ratings | **292** | 7 |
| Positive reviews | 81.3% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Monthly** | Every 3 months |
| Monetization | Subscription | **Free** |
| Size | 94 MB | 2 MB |
| Requires iOS | 16.6 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [MCC (BV)](https://appshunter.io/developer/421126411) | [Studio BabDreams](https://appshunter.io/developer/431517875) |

## What reviewers say

### B737 MRG

[App page](https://appshunter.io/ios/app/b737-mrg/id481163421)

This professional reference app provides airline pilots with detailed guidance and practical advice for handling over 300 non-normal situations on the Boeing 737. It includes extensive system notes, illustrations, logic gates, and schematics to aid in-flight and ground operations.

**Highlights:** 300+ non-normal procedures, System notes and practical advice, Over 2,200 illustrations, Logic gates and schematics, Covers CL, NG, MAX editions, Regular content updates

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Yearly Subscription | $9.99 | per year |

**What reviewers like**

- 🚀 Excellent resource for 737 pilots
- 👍 Detailed and comprehensive information
- 🔍 Helpful for training and sim prep
- 💡 Provides deeper understanding of systems and procedures
- 🤓 Valuable addition to company manuals

**What reviewers complain about**

- 🐛 Occasional app crashes and bugs
- 💰 Transition to subscription model frustrates some users
- 📱 Compatibility issues with some iOS updates

**Reported bugs**

- App crashing on startup after updates
- Losing downloaded data on app restart
- Difficulty exiting demo mode

**Requested features**

- Interactive features like switchable diagrams
- Availability on macOS/desktop platforms


### 737 Master Caution

[App page](https://appshunter.io/ios/app/737-master-caution/id6455042070)

This app provides a comprehensive reference for over 200 warning lights and messages across B737 Classic, NG, and MAX aircraft families. It includes tools for abbreviations, FMC messages, circuit breakers, and electrical buses, aiding pilot training and aviation enthusiasts.

**Highlights:** References over 200 B737 warning lights and messages, Filter by aircraft family (Classic, NG, MAX), Full text search for specific lights, Personal notes and bookmarking, Reference tools for abbreviations, FMC messages, circuit breakers, and electrical buses

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

**In-app purchases:** none


## Frequently asked questions

### Is B737 MRG free?

B737 MRG is free to download, with in-app purchases available.

### Is 737 Master Caution free?

737 Master Caution is free to download, with no in-app purchases.

### Which has better reviews, B737 MRG or 737 Master Caution?

B737 MRG is rated higher. B737 MRG averages 4.9 out of 5 from 292 ratings, while 737 Master Caution averages 4.4 from 7 ratings.

### Do B737 MRG or 737 Master Caution have ads?

Neither B737 MRG nor 737 Master Caution shows ads.

### Which is updated more often, B737 MRG or 737 Master Caution?

B737 MRG ships an update monthly, and 737 Master Caution every 3 months. Most recently, B737 MRG was updated on September 26, 2026 and 737 Master Caution on September 10, 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.*