# Emerald Chronometer vs Atomic Clock PRO

The clearest difference is in-app purchases: Emerald Chronometer at none against Atomic Clock PRO's 2. Emerald Chronometer also leads on review sentiment (97% vs 73%) and rating (4.9 vs 4.7). Atomic Clock PRO's advantage is update cadence (every 3 months vs every 22 months) and ratings volume (10K vs 105). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Atomic Clock PRO sells 2 in-app purchases, starting at $1.99 per month. Emerald Chronometer asks for nothing beyond the download.

Emerald Chronometer holds the better App Store score, 4.9 against 4.7. That said, the two scores are not equally well evidenced: Atomic Clock PRO has 10K ratings behind it against 105, so its average is the more settled of the two. Written reviews point the same way: 97% of Emerald Chronometer's written reviews are positive against 73% of Atomic Clock PRO's.

Emerald Chronometer ships an update every 22 months, Atomic Clock PRO every 3 months. The most recent releases landed on October 6, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Emerald Chronometer | Atomic Clock PRO |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (105 ratings)](https://appshunter.io/ios/app/emerald-chronometer/id284953670/reviews)** | [4.7 (10K ratings)](https://appshunter.io/ios/app/atomic-clock-pro/id899090224/reviews) |
| Number of ratings | 105 | **10K** |
| Positive reviews | **96.8% of reviews** | 73.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | — | Yes |
| Update frequency | Every 22 months | **Every 3 months** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 311 MB | 6 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Scapa Flow, LLC](https://appshunter.io/developer/635350184) | [Brachmann Online Marketing GmbH & Co. KG](https://appshunter.io/developer/682848918) |

## What reviewers say

### Emerald Chronometer

[App page](https://appshunter.io/ios/app/emerald-chronometer/id284953670)

Experience highly detailed mechanical watch faces with advanced astronomical and clock complications. Track celestial events, manage time with precision, and explore historical and future dates with interactive displays. Optimized for iPhone and iPod touch.

**Highlights:** Accurate astronomical data (4000 BCE - 2800 CE), Sun, Moon, and planet rise/set times, Mechanical display of Moon phases, Precise local and UTC time, Chronograph with split timer, World-time and calendar watches, Interactive time-travel simulation

**In-app purchases:** none


### Atomic Clock PRO

[App page](https://appshunter.io/ios/app/atomic-clock-pro/id899090224)

Get the most accurate time from an official atomic clock server. This app automatically detects your time zone and allows custom backgrounds. Easily switch between digital and analog clock displays with a swipe.

**Highlights:** Exact time from atomic clock, Automatic time zone recognition, Customizable background images, Digital and analog clock modes, Optional sound alerts, Color customization

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $1.99 | per month |
| Remove Ads | $5.99 | one-time |

**What reviewers like**

- ⭐ Accurate time display
- 📟 Useful for timing events
- 🕰️ Helpful for setting other clocks
- 🔍 Large, easy-to-read clock face

**What reviewers complain about**

- 💸 Subscription model for ad-free version
- 📢 Excessive advertisements
- 🔍 Small font for seconds display
- 🔀 Difficulty in displaying both analog and digital clocks simultaneously

**Reported bugs**

- Second hand occasionally runs in reverse
- Digital clock display cuts off on some devices
- Inconsistent behavior when switching between clock types

**Requested features**

- Customizable clock face options
- Ability to set widget on home screen
- Sync with system clock to automatically update time


## Frequently asked questions

### Is Emerald Chronometer free?

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

### Is Atomic Clock PRO free?

Atomic Clock PRO is free to download, with in-app purchases available.

### Which has better reviews, Emerald Chronometer or Atomic Clock PRO?

Emerald Chronometer is rated higher. Emerald Chronometer averages 4.9 out of 5 from 105 ratings, while Atomic Clock PRO averages 4.7 from 10K ratings.

### Which is updated more often, Emerald Chronometer or Atomic Clock PRO?

Emerald Chronometer ships an update every 22 months, and Atomic Clock PRO every 3 months. Most recently, Emerald Chronometer was updated on October 6, 2026 and Atomic Clock PRO on October 13, 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.*