# B737 CDU vs 737 Master Caution

The clearest difference is price: 737 Master Caution at Free against B737 CDU's $7.99. 737 Master Caution also leads on rating (4.4 vs 2.0) and device support (3 vs 1). B737 CDU's advantage is iOS requirement (8.0 vs 13.0). On update cadence, ads and in-app purchases there is nothing between them.

737 Master Caution is free to download; B737 CDU costs $7.99 up front. Neither carries in-app purchases, so what you see is what you pay.

737 Master Caution holds the better App Store score, 4.4 against 2.0. Both are backed by a comparable volume of ratings — 2 and 7 respectively.

B737 CDU ships an update every 2 months, 737 Master Caution every 3 months. Both last shipped on October 15, 2026.

## The numbers

| Metric | B737 CDU | 737 Master Caution |
| --- | --- | --- |
| Price | $7.99 | **Free** |
| Rating | [2.0 (2 ratings)](https://appshunter.io/ios/app/b737-cdu/id1522267697/reviews) | **[4.4 (7 ratings)](https://appshunter.io/ios/app/737-master-caution/id6455042070/reviews)** |
| Number of ratings | 2 | **7** |
| Positive reviews | 42.9% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 3 months |
| Monetization | Paid | **Free** |
| Size | 43 MB | 2 MB |
| Requires iOS | **8.0** | 13.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Kun-Woo Go](https://appshunter.io/developer/1775137171) | [Studio BabDreams](https://appshunter.io/developer/431517875) |

## What reviewers say

### B737 CDU

[App page](https://appshunter.io/ios/app/b737-cdu/id1522267697)

This app simulates a Boeing 737 CDU, allowing users to explore its pages and enter data. It's designed for pilots preparing for flights or seeking a refresher on CDU operations. The tool offers touch screen navigation and access to FMC and ACARS pages.

**Highlights:** Simulates 737 CDU interface, Explore FMC and ACARS pages, Touch screen navigation, Data entry for CDU, Useful for pilot training

**Features:** macOS Compatibility

**In-app purchases:** none


### 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 CDU free?

B737 CDU costs $7.99, with no in-app purchases.

### Is 737 Master Caution free?

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

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

737 Master Caution is rated higher. B737 CDU averages 2.0 out of 5 from 2 ratings, while 737 Master Caution averages 4.4 from 7 ratings.

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

Neither B737 CDU nor 737 Master Caution shows ads.

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

B737 CDU ships an update every 2 months, and 737 Master Caution every 3 months. Most recently, B737 CDU was updated on October 15, 2026 and 737 Master Caution on October 15, 2026.

---

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