# AtomicClock vs ChronoLog

The clearest difference is ads: ChronoLog at none against AtomicClock's shown. ChronoLog also leads on iOS requirement (15.0 vs 17.4). AtomicClock's advantage is ratings volume (5.6K vs 238) and monetization model (free with in-app purchases vs paid). On price, rating, review sentiment and update cadence there is nothing between them.

Both are free to download. AtomicClock sells 1 one-off in-app purchase and ChronoLog sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

AtomicClock holds the better App Store score, 4.8 against 4.6. That said, the two scores are not equally well evidenced: AtomicClock has 5.6K ratings behind it against 238, so its average is the more settled of the two. Written reviews split almost evenly too, at 84% and 85% positive.

AtomicClock ships an update monthly, ChronoLog every 3 weeks. The most recent releases landed on November 6, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | AtomicClock | ChronoLog |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (5.6K ratings)](https://appshunter.io/ios/app/atomicclock-ntp-time/id1402993049/reviews)** | [4.6 (238 ratings)](https://appshunter.io/ios/app/chronolog-watch-accuracy/id6452083510/reviews) |
| Number of ratings | **5.6K** | 238 |
| Positive reviews | 84.3% of reviews | **85.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Monthly | **Every 3 weeks** |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 17 MB | 50 MB |
| Requires iOS | 17.4 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Timo Partl](https://appshunter.io/developer/1387413672) | [tyler wood](https://appshunter.io/developer/1698739777) |

## What reviewers say

### AtomicClock

[App page](https://appshunter.io/ios/app/atomicclock-ntp-time/id1402993049)

This app displays the exact current time synchronized with NTP servers, offering a customizable clock view for precise time checks. It's ideal for setting watches, verifying timestamps, or comparing local and network time.

**Highlights:** Precise time from NTP servers, Customizable clock faces, Select or add time servers, Local and UTC views, 12/24 hour modes, Customizable time format, Acoustic ticking

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Pro Version | $6.99 | one-time |

**What reviewers like**

- 🚀 Accurate time
- 👍 Highly customizable
- 🚀 Precise to the second
- 👍 Easy to use
- 👍 Helpful for setting watches

**What reviewers complain about**

- 🐛 Server connection issues
- 🔍 Limited time zone options
- 💰 Ads diminish clock view
- 🔍 Lacks some advanced features
- 🔍 Redundant for some users

**Reported bugs**

- Crashes on certain iOS versions
- Occasional freezing of hands
- Countdown timer sound not working

**Requested features**

- Add GMT/dual time display
- Implement widget support
- Add different second hand sounds
- Allow setting background color to match watch
- Include alarm/timer functionality


### 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 AtomicClock free?

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

### Is ChronoLog free?

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

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

AtomicClock is rated higher. AtomicClock averages 4.8 out of 5 from 5.6K ratings, while ChronoLog averages 4.6 from 238 ratings.

### Do AtomicClock or ChronoLog have ads?

AtomicClock shows ads; ChronoLog does not.

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

AtomicClock ships an update monthly, and ChronoLog every 3 weeks. Most recently, AtomicClock was updated on November 6, 2026 and ChronoLog on November 7, 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.*