# WatchM3 vs Castomètre

The clearest difference is device support: WatchM3 at 5 against Castomètre's 2. Castomètre's advantage is iOS requirement (16.2 vs 27.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on November 8, 2026 and November 9, 2026 respectively.

## The numbers

| Metric | WatchM3 | Castomètre |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Size | 2 MB | 4 MB |
| Requires iOS | 27.0 | **16.2** |
| Devices | **iPhone, iPad, Mac, Apple Watch, Vision Pro** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [David Larose](https://appshunter.io/developer/1537994900) | [CASTORAMA FRANCE](https://appshunter.io/developer/353499905) |

## What reviewers say

### WatchM3

[App page](https://appshunter.io/ios/app/watchm3/id6504363924)

**Features:** Apple Watch app

**In-app purchases:** none


### Castomètre

[App page](https://appshunter.io/ios/app/castometre/id6760836501)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is WatchM3 free?

WatchM3 is free to download, with no in-app purchases.

### Is Castomètre free?

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

### Do WatchM3 or Castomètre have ads?

Neither WatchM3 nor Castomètre shows ads.

### Which is updated more often, WatchM3 or Castomètre?

WatchM3 ships an update every 3 weeks, and Castomètre every 3 weeks. Most recently, WatchM3 was updated on November 8, 2026 and Castomètre on November 9, 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.*