# Average ISA Deviation vs AeroNOTAM

The clearest difference is price: AeroNOTAM at Free against Average ISA Deviation's $3.99. AeroNOTAM also leads on update cadence (every 3 months vs every 14 months) and ratings volume (20 vs 2). Average ISA Deviation's advantage is review sentiment (67% vs 27%) and in-app purchases (none vs 2). On rating, ads and device support there is nothing between them.

AeroNOTAM is free to download; Average ISA Deviation costs $3.99 up front. AeroNOTAM sells 2 one-off in-app purchases. Average ISA Deviation asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 3.5 for Average ISA Deviation against 3.5 for AeroNOTAM. That said, the two scores are not equally well evidenced: AeroNOTAM has 20 ratings behind it against 2, so its average is the more settled of the two. Written reviews are what separate them: 67% of Average ISA Deviation's written reviews are positive against 27% of AeroNOTAM's.

Average ISA Deviation ships an update every 14 months, AeroNOTAM every 3 months. The most recent releases landed on August 1, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Average ISA Deviation | AeroNOTAM |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [3.5 (2 ratings)](https://appshunter.io/ios/app/average-isa-deviation/id630933637/reviews) | [3.5 (20 ratings)](https://appshunter.io/ios/app/aeronotam/id918926129/reviews) |
| Number of ratings | 2 | **20** |
| Positive reviews | **66.7% of reviews** | 27.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 14 months | **Every 3 months** |
| Monetization | **Paid** | Subscription |
| Size | 1 MB | 12 MB |
| Requires iOS | 26.1 | **14.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Juan Mauricio Padilla Villarreal](https://appshunter.io/developer/604279584) | [Lakehorn AG](https://appshunter.io/developer/288286082) |

## What reviewers say

### 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


### AeroNOTAM

[App page](https://appshunter.io/ios/app/aeronotam/id918926129)

Access NOTAMs worldwide with offline data management, map views, and customizable notifications. Organize routes by flightpath, airport, or map radius. Share NOTAMs easily via various platforms.

**Highlights:** Offline NOTAM data management, Map view with radius definition, Customizable notifications for alerts, Bookmark and share NOTAMs, Multiple list views, Background refresh

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 2 Months | $0.99 | one-time |
| 12 Months | $3.39 | one-time |


## Frequently asked questions

### Is Average ISA Deviation free?

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

### Is AeroNOTAM free?

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

### Which has better reviews, Average ISA Deviation or AeroNOTAM?

Average ISA Deviation and AeroNOTAM are both rated 3.5 out of 5 on the App Store, from 2 and 20 ratings respectively.

### Do Average ISA Deviation or AeroNOTAM have ads?

Neither Average ISA Deviation nor AeroNOTAM shows ads.

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

Average ISA Deviation ships an update every 14 months, and AeroNOTAM every 3 months. Most recently, Average ISA Deviation was updated on August 1, 2026 and AeroNOTAM on September 24, 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.*