# Calibration Keeper vs W

The clearest difference is update cadence: W at every 3 months against Calibration Keeper's every 16 months. On price, ads, in-app purchases and device support there is nothing between them.

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

Calibration Keeper ships an update every 16 months, W every 3 months. The most recent releases landed on October 3, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Calibration Keeper | W |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 16 months | **Every 3 months** |
| Size | 22 MB | 29 MB |
| Requires iOS | 15.1 | **15** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Trihydro Corporation](https://appshunter.io/developer/920601995) | [LumenRadio AB](https://appshunter.io/developer/1443137236) |

## What reviewers say

### Calibration Keeper

[App page](https://appshunter.io/ios/app/calibration-keeper/id1465790622)

**Features:** macOS Compatibility

**In-app purchases:** none


### W

[App page](https://appshunter.io/ios/app/w-modbus/id6472275984)

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

**In-app purchases:** none


## Frequently asked questions

### Is Calibration Keeper free?

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

### Is W free?

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

### Do Calibration Keeper or W have ads?

Neither Calibration Keeper nor W shows ads.

### Which is updated more often, Calibration Keeper or W?

Calibration Keeper ships an update every 16 months, and W every 3 months. Most recently, Calibration Keeper was updated on October 3, 2026 and W on October 10, 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.*