Comparison

B737 MRG vs 737 Master Caution

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

B737 MRG

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
Read full description

The B737MRG is the most trusted professional reference for airline pilots flying the Boeing 737. The B737MRG covers 300 different non-normals, that is a hundred more than the official QRH. The app provides system notes and practical advice on how to deal with each non-normal, both on ground and in flight. The app comes with over 2,200 illustrations, logic gates, lights and schematics! Captain Pat BOONE, author of the B737 MRG, is a senior instructor with more than 20,000 flight hours on Boeing aircraft (Boeing 737, Boeing 767 and Boeing 787 Dreamliner). You can free download the app and review a couple of demo pages. You need a paid subscription to access the entire content. With a subscription you get access to all editions of the B737MRG (CL, NG, MAX) in all languages (English, Chinese). Your subscription includes all updates of the content that are published by the author on a regular basis. Subscription details: Your subscription runs for a period of 1 year, starting the date of in-app purchase. There is no free trial period. The price for the subscription is around a dollar / euro per month. The exact price depends on local taxes and is displayed inside the app. A single subscription can be used on multiple devices (phone, tablet), as long as these devices run the same app store account. Cancellation and refund of your current subscription are not possible. Your subscription runs until the end of the current period. Your subscription is automatically renewed, unless Auto-Renew is turned off at least 24 hours before the end of the current period. Your app store account will be charged for renewal within 24 hours prior to the end of the current period. You can turn-off auto-renewal by going to your app store account settings, anytime after your initial purchase. Terms and Conditions & Privacy Policy : Visit : https://b737mrg.net/disclaimer/

About

737 Master Caution

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
Read full description

This app references more than 200 warning lights and messages of the B737 Classic, NG and MAX families. You are a pilot preparing your initial 737 type rating training, or an aviation enthusiast, or a flight simulator fan. You should enjoy this app. - Warning lights are grouped by FCOM chapters. - You may filter warning lights by airplane family / generation (Classic, NG or MAX). - Full text search to find a specific light. - Add your personal notes for each light and use the app as a notebook. - Place a bookmark to specific warning lights. You will also find 4 other tools, as reference : - A complete list of abbreviations with more than 400 definitions. - Full explanation of more than 100 FMC messages. - Position of more than 500 circuit breakers, sorted by ATA codes or by panels. - List of all electrical buses and more than 500 associated services. A great tool during your initial type rating training or during a refresher later. For training purposes ONLY. Do not use in-flight. Should you spot any error or have any suggestion, feel free to contact : support@babdreams.com Enjoy.

Screenshots

B737 MRG4 screens
737 Master Caution4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

B737 MRG ships an update monthly, 737 Master Caution every 3 months. The most recent releases landed on September 22, 2026 and September 10, 2026 respectively.

Scorecard6 real differences · 4 level
B737 MRG versus 737 Master Caution: the parameters behind the verdict, then further details
ParameterB737 MRG737 Master Caution
PriceFreeFree
Rating4.9 (292 ratings) — better4.4 (7 ratings)
Positive reviews81.3% of reviews—
Number of ratings292 — better7
Update frequencyMonthly — betterEvery 3 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationSubscriptionFree — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.613.0 — better
Further details — not scored
Size94 MB2 MB
Age rating4+4+
DeveloperMCC (BV)Studio BabDreams

Customer experience

B737 MRG

All ratings292 ratings
Positive97.9%
Neutral0.3%
Negative1.7%
Written reviews182 reviews
Positive81.3%
Neutral1.1%
Negative17.6%

737 Master Caution

All ratings7 ratings
Positive85.7%
Neutral0.0%
Negative14.3%

Bugs and requests

B737 MRG

Reported bugs

3 issues
  • App crashing on startup after updates
  • Losing downloaded data on app restart
  • Difficulty exiting demo mode

Requested features

2 requests
  • Interactive features like switchable diagrams
  • Availability on macOS/desktop platforms

737 Master Caution

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

B737 MRG

Subscriptions1
  • Yearly Subscription$9.991 Year
None

737 Master Caution

No in-app purchases

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 22, 2026 and 737 Master Caution on September 10, 2026.

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