# CITIZEN Eco vs AtomicClock

The clearest difference is review sentiment: AtomicClock at 84% against CITIZEN Eco's 0%. AtomicClock also leads on update cadence (monthly vs every 5 months). CITIZEN Eco's advantage is in-app purchases (none vs 1) and ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. AtomicClock sells 1 one-off in-app purchase. CITIZEN Eco asks for nothing beyond the download.

CITIZEN Eco ships an update every 5 months, AtomicClock monthly. The most recent releases landed on September 25, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | CITIZEN Eco | AtomicClock |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.8 (5.6K ratings)](https://appshunter.io/ios/app/atomicclock-ntp-time/id1402993049/reviews)** |
| Number of ratings | — | **5.6K** |
| Positive reviews | 0.0% of reviews | **84.3% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 months | **Monthly** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 67 MB | 17 MB |
| Requires iOS | **15.6** | 17.4 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [CITIZEN WATCH CO.,LTD](https://appshunter.io/developer/434806605) | [Timo Partl](https://appshunter.io/developer/1387413672) |

## What reviewers say

### CITIZEN Eco

[App page](https://appshunter.io/ios/app/citizen-eco-drive-bluetooth-s/id1268478800)

This app connects your smartphone to compatible watches, allowing you to sync time, set alarms, and receive notifications for calls and messages. It also features world time settings and a light level indicator for the watch's power source.

**Highlights:** Automatic time synchronization, World time settings, Call and message notifications, Customizable alarms, Light level indicator, Smartphone search function, Link loss alerts

**Features:** macOS Compatibility

**In-app purchases:** none


### 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


## Frequently asked questions

### Is CITIZEN Eco free?

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

### Is AtomicClock free?

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

### Do CITIZEN Eco or AtomicClock have ads?

AtomicClock shows ads; CITIZEN Eco does not.

### Which is updated more often, CITIZEN Eco or AtomicClock?

CITIZEN Eco ships an update every 5 months, and AtomicClock monthly. Most recently, CITIZEN Eco was updated on September 25, 2026 and AtomicClock on October 29, 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.*