III vs B737 MRG
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
III
Calculate material properties for III-V compound semiconductors like AlGaInAsP. It determines compositions, lattice constant, strain, bandgap, and effective masses for InP or GaAs substrates.
- III-V compound semiconductor calculations
- Material property determination
- Composition calculation (x, y, z)
- Lattice constant and strain analysis
- Bandgap and effective mass calculation
- Supports InP and GaAs substrates
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Application to calculate the compositions and material properties of a III-V compound semiconductor. Either InP or GaAs is assumed for the substrate. Some of the compositions and material parameters of the AlGaInAsP compound semiconductor are specified to determine the remain unknown parameters. The following properties are shown as a result: compositions (x, y, z), lattice constant, strain, bandgap, relative energy positions of the conduction and valence bands, and effective masses of the electron and holes.
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.
- 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
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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/
Screenshots
Verdict
The clearest difference is price: B737 MRG at Free against III's $2.99. B737 MRG also leads on rating (4.9 vs 4.0) and update cadence (monthly vs every 17 months). III's advantage is in-app purchases (none vs 1) and review sentiment (100% vs 81%). On 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
B737 MRG is free to download; III costs $2.99 up front. B737 MRG sells 1 in-app purchase, starting at $9.99 per year. III asks for nothing beyond the download.
B737 MRG holds the better App Store score, 4.9 against 4.0. That said, the two scores are not equally well evidenced: B737 MRG has 292 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 100% of III's written reviews are positive against 81% of B737 MRG's, so the app with the better star average is not the one people write more warmly about.
III ships an update every 17 months, B737 MRG monthly. The most recent releases landed on October 2, 2026 and October 13, 2026 respectively.
| Parameter | III | B737 MRG |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 4.0 (1 ratings) | 4.9 (292 ratings) — better |
| Positive reviews | 100.0% of reviews — better | 81.3% of reviews |
| Number of ratings | 1 | 292 — better |
| Update frequency | Every 17 months | Monthly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid — better | Subscription |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 11.0 — better | 16.6 |
| Further details — not scored | ||
| Size | 10 MB | 94 MB |
| Age rating | 4+ | 4+ |
| Developer | Takuya Ishikawa | MCC (BV) |
Customer experience
III
B737 MRG
Bugs and requests
III
Not enough reviews yet to summarise bugs or 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
In-app purchases
III
No in-app purchases
B737 MRG
- Yearly Subscription$9.991 Year
