# B737 Alerts vs Average ISA Deviation

The clearest difference is rating: Average ISA Deviation at 5.0 against B737 Alerts's 4.3. Average ISA Deviation also leads on review sentiment (67% vs 38%) and price ($3.99 vs $9.99). B737 Alerts's advantage is update cadence (every 5 months vs every 14 months) and ratings volume (9 vs 2). On ads, in-app purchases, monetization model and device support there is nothing between them.

B737 Alerts costs $9.99 and Average ISA Deviation $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Average ISA Deviation holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 9 and 2 respectively. Written reviews point the same way: 38% of B737 Alerts's written reviews are positive against 67% of Average ISA Deviation's.

B737 Alerts ships an update every 5 months, Average ISA Deviation every 14 months. The most recent releases landed on October 26, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | B737 Alerts | Average ISA Deviation |
| --- | --- | --- |
| Price | $9.99 | **$3.99** |
| Rating | [4.3 (9 ratings)](https://appshunter.io/ios/app/b737-alerts/id453260249/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/average-isa-deviation/id630933637/reviews)** |
| Number of ratings | **9** | 2 |
| Positive reviews | 37.5% of reviews | **66.7% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 14 months |
| Monetization | Paid | Paid |
| Size | 54 MB | 1 MB |
| Requires iOS | **9.0** | 26.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [fss.aero](https://appshunter.io/developer/446805306) | [Juan Mauricio Padilla Villarreal](https://appshunter.io/developer/604279584) |

## What reviewers say

### B737 Alerts

[App page](https://appshunter.io/ios/app/b737-alerts/id453260249)

A comprehensive reference guide for Boeing 737 error messages, covering PFD/ND, FMC, and panel module issues. It provides detailed descriptions, corrective actions, and cross-links to procedures for pilots and maintenance personnel.

**Highlights:** Covers 737-600, -700, -800, -900, and BBJ series errors, Details PFD/ND, FMC, and panel module errors, Includes nearly 400 errors, Cross-links annunciations to QRH procedures, Provides error descriptions and corrective actions, Classifies messages by system and ATA chapter

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

**In-app purchases:** none


### Average ISA Deviation

[App page](https://appshunter.io/ios/app/average-isa-deviation/id630933637)

This utility helps professional pilots quickly calculate average ISA temperature deviation for descent planning on specific aircraft models. It simplifies manual calculations, reduces workload, and operates offline, making it ideal for cockpit use.

**Highlights:** Calculate average ISA deviation, Reduce descent planning workload, Simplify manual calculations, Offline cockpit use, Designed by a pilot

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

**In-app purchases:** none


## Frequently asked questions

### Is B737 Alerts free?

B737 Alerts costs $9.99, with no in-app purchases.

### Is Average ISA Deviation free?

Average ISA Deviation costs $3.99, with no in-app purchases.

### Which has better reviews, B737 Alerts or Average ISA Deviation?

Average ISA Deviation is rated higher. B737 Alerts averages 4.3 out of 5 from 9 ratings, while Average ISA Deviation averages 5.0 from 2 ratings.

### Do B737 Alerts or Average ISA Deviation have ads?

Neither B737 Alerts nor Average ISA Deviation shows ads.

### Which is updated more often, B737 Alerts or Average ISA Deviation?

B737 Alerts ships an update every 5 months, and Average ISA Deviation every 14 months. Most recently, B737 Alerts was updated on October 26, 2026 and Average ISA Deviation on October 23, 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.*