# Magnetometer vs ChronoLog

The clearest difference is price: ChronoLog at Free against Magnetometer's $0.99. ChronoLog also leads on update cadence (every 3 weeks vs every 34 months) and rating (4.6 vs 4.4). Magnetometer's advantage is in-app purchases (none vs 2). On review sentiment, ads, monetization model and iOS requirement there is nothing between them.

ChronoLog is free to download; Magnetometer costs $0.99 up front. ChronoLog sells 2 one-off in-app purchases. Magnetometer asks for nothing beyond the download.

ChronoLog holds the better App Store score, 4.6 against 4.4. That said, the two scores are not equally well evidenced: ChronoLog has 236 ratings behind it against 13, so its average is the more settled of the two. Written reviews split almost evenly too, at 86% and 85% positive.

Magnetometer ships an update every 34 months, ChronoLog every 3 weeks. Both last shipped on November 3, 2026.

## The numbers

| Metric | Magnetometer | ChronoLog |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [4.4 (13 ratings)](https://appshunter.io/ios/app/magnetometer/id1662997574/reviews) | **[4.6 (236 ratings)](https://appshunter.io/ios/app/chronolog-watch-accuracy/id6452083510/reviews)** |
| Number of ratings | 13 | **236** |
| Positive reviews | **85.7% of reviews** | 85.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 34 months | **Every 3 weeks** |
| Monetization | Paid | Paid |
| Size | 2 MB | 50 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Bogdan Gavriluta](https://appshunter.io/developer/1584690995) | [tyler wood](https://appshunter.io/developer/1698739777) |

## What reviewers say

### Magnetometer

[App page](https://appshunter.io/ios/app/magnetometer/id1662997574)

This application uses your iPhone's compass to detect electromagnetic interference, helping you find metal objects or magnets. It's designed for fun and experimental purposes, not as a professional tool. Discover hidden metal items or simply explore the magnetic fields around you.

**Highlights:** Detects metal and magnets, Uses iPhone's compass, Measures EMF interference, Fun and experimental use, Simple user interface

**In-app purchases:** none


### ChronoLog

[App page](https://appshunter.io/ios/app/chronolog-watch-accuracy/id6452083510)

This app provides professional-grade tools to track the accuracy of mechanical watches. It offers audio timegraphing, photo offset measurement, and tap timing, along with detailed analytics and atomic time synchronization for collectors and enthusiasts.

**Highlights:** Audio timegrapher for rate, beat error, and amplitude, Photo offset measurement against atomic time, Tap timing for quick offset logging, Track accuracy trends over time, Atomic time synchronization, Detailed performance graphs and analytics, Manage and organize watch collection

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $5.99 | one-time |
| Premium | $6.99 | one-time |


## Frequently asked questions

### Is Magnetometer free?

Magnetometer costs $0.99, with no in-app purchases.

### Is ChronoLog free?

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

### Which has better reviews, Magnetometer or ChronoLog?

ChronoLog is rated higher. Magnetometer averages 4.4 out of 5 from 13 ratings, while ChronoLog averages 4.6 from 236 ratings.

### Do Magnetometer or ChronoLog have ads?

Neither Magnetometer nor ChronoLog shows ads.

### Which is updated more often, Magnetometer or ChronoLog?

Magnetometer ships an update every 34 months, and ChronoLog every 3 weeks. Most recently, Magnetometer was updated on November 3, 2026 and ChronoLog on November 3, 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.*