# HamWatch vs CairnOS

The clearest difference is price: CairnOS at Free against HamWatch's $4.99. CairnOS also leads on update cadence (every 4 days vs every 10 days). HamWatch's advantage is iOS requirement (16.6 vs 18.0). On rating, ratings volume, ads and in-app purchases there is nothing between them.

CairnOS is free to download; HamWatch costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for HamWatch against 5.0 for CairnOS. Both are backed by a comparable volume of ratings — 3 and 2 respectively.

HamWatch ships an update every 10 days, CairnOS every 4 days. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | HamWatch | CairnOS |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | [5.0 (3 ratings)](https://appshunter.io/ios/app/hamwatch/id6749077658/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/cairnos/id6819076554/reviews) |
| Number of ratings | **3** | 2 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 10 days | **Every 4 days** |
| Monetization | Paid | **Free** |
| Size | 6 MB | 54 MB |
| Requires iOS | **16.6** | 18.0 |
| Devices | iPhone, Apple Watch | iPhone, iPad |
| Age rating | +4 | 4+ |
| Developer | [James Krepelka](https://appshunter.io/developer/1828469331) | [Christopher Van Hoose](https://appshunter.io/developer/1510007987) |

## What reviewers say

### HamWatch

[App page](https://appshunter.io/ios/app/hamwatch/id6749077658)

This app provides amateur radio operators with essential tools on their Apple Watch. Monitor real-time space weather data and track POTA spots directly from your wrist. Customizable complications display your call sign on your watch face.

**Highlights:** Real-time space weather monitoring, 24-hour historical space weather charts, POTA spot tracking on wrist, Customizable watch face complications, Seamless iPhone and Apple Watch sync, Configurable auto-refresh intervals

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### CairnOS

[App page](https://appshunter.io/ios/app/cairnos/id6819076554)

Communicate off-grid using a mesh network of radios. Send messages, monitor network status, and explore maps without cell service or internet. Features include direct messages, channels, and on-device translation.

**Highlights:** LoRa mesh network communication, Direct messages and channels, On-device message translation, Network status dashboard, Offline map downloads, Message signing and verification

**Features:** macOS Compatibility, Siri integration, Vision Pro support, iPhone Duo support

**In-app purchases:** none


## Frequently asked questions

### Is HamWatch free?

HamWatch costs $4.99, with no in-app purchases.

### Is CairnOS free?

CairnOS is free to download, with no in-app purchases.

### Which has better reviews, HamWatch or CairnOS?

HamWatch and CairnOS are both rated 5.0 out of 5 on the App Store, from 3 and 2 ratings respectively.

### Do HamWatch or CairnOS have ads?

Neither HamWatch nor CairnOS shows ads.

### Which is updated more often, HamWatch or CairnOS?

HamWatch ships an update every 10 days, and CairnOS every 4 days. Most recently, HamWatch was updated on November 5, 2026 and CairnOS on October 31, 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.*