# Atomic Clock

> Ultra-precise atomic clock with millisecond accuracy and time synchronization. (iPhone/iPad app by Awyse.)

- Source: https://appshunter.io/ios/app/atomic-clock/id291668819 (this page in markdown: same URL + `.md`)
- Developer: [Awyse](https://appshunter.io/developer/291668822)
- Category: Reference, Utilities
- Price: $2.99 with in-app purchases
- Rating: 2.64/5 from 22 App Store ratings · 50 written reviews indexed
- Age rating: 4+
- Requires: iOS 8.2 · 25 MB
- Languages: English
- Released: 2019-02-01
- Data updated: 2026-06-10
- Monetization: freemium
- User reviews in markdown: https://appshunter.io/ios/app/atomic-clock/id291668819/reviews.md

## What is Atomic Clock?

***Ultra Precise, Ultra Accurate, Millisecond Atomic Clock Synced***

Includes FREE Apple Watch app to display accurate Second and Centisecond.

Your goal is to remain the most accurate mobile clock on mobile.

The Atomic Clock App displays Milliseconds, and accuracy of your device in millisecond.


V 4.7
down to 38 Millisecond accuracy,
PPS(Pulse Per Second) under a Millisecond  0.050 ms


Detailed features:

- Accuracy down to 1 Millisecond (Without subscription 5 centiseconds)

- Syncing to a network of time reference servers up to 16 in USA for better accuracy(Without subscription 1 server)

- Auto syncing continuously

- Display the device clock(With subscription)

- Show the time difference between the device and the official time(With subscription)

- Reference time for Asia/Europe/USA

- Jump between 2 time zone (Time Zone or local)

- Audio signal per second ON/OFF (PPS)

- 4 different alarm sounds

- Multi push alarms on multi time zones

- Multi time zones alarms 


- Up to date Time zone table :
• official time zones
• military time
• aeronautical time
• astronomical time

from V 4.3:

Accuracy of the time is displayed in Milliseconds
A Pulse per Second timer is included
Multiple sources of reference time can be choose

Version 4.2 achieve to be precise at 2 millisecond in every set of 10 sec,(Pulse Per Second, PPS)

## Key features

- Millisecond accuracy
- Network time server syncing
- Continuous auto-syncing
- Pulse Per Second (PPS) signal
- Multiple alarm sounds
- Multi-time zone alarms
- Up-to-date time zone table

## Pricing and in-app purchases

Base price: $2.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| 1 Year Live Synced Centiscecond Reference Time | $3.99 | one-time |


## Recent user reviews (10 of 50)

All indexed reviews: https://appshunter.io/ios/app/atomic-clock/id291668819/reviews.md

### 3/5 — Minute hand is always half a minute behind!

*2020-03-09, version 4.7*

I used to love this app, but now the minute hand is always half a minute behind, so it’s hard to tell at a glance what time it is with any precision. For an app whose very design screams precision, this is just incredible.

I can only guess that it’s not been updated in a few years so it no longer works well in recent iOS versions. If that’s not the case, then it’s a mystery why it now has this major defect.

### 2/5 — iWatch support..

*2019-02-23, version 4.7*

Tried to open the app on my watch today. Claimed that it could not open because it needs an update. Been 2 years since the last update. 4 stars overall but removed 2 stars from this review due to it no longer working on my iWatch.

### 3/5 — Does not support iPad

*2019-01-17, version 4.7*

The app is great and visually attractive, but it appears to be for iPhone or watch only, as it is portrait mode only. The app cannot change to landscape mode.

To the developer- please include landscape in a future update! I had hoped to use this for a cabinet clock for display purposes, but cannot because of this problem.

### 1/5 — Very Accurate! But....

*2018-12-17, version 4.7*

But, the Apple Watch app doesn’t seem to exist.

### 5/5 — Great App!

*2018-11-12, version 4.7*

To the guy with the “misleading” review, this app was not meant as an Apple Watch face; it’s an atomic clock.

App is great and very accurate!  Allows several different sources too.

### 1/5 — NOT a watch face !!!!! Just a time app for your phone.

*2018-04-10, version 4.7*

This is placed In The Watch face section . This is not a watch face ! The ad is very misleading . Nothing more than a accurate time app that you can get free other places .

### 1/5 — Fraud

*2017-07-01, version 4.7*

Not a watch face....do not buy

### 1/5 — BS NOT a watch face.

*2017-03-21, version 4.7*

Don't buy if you looking for a watch face.  I will make sure this app gets pulled.   Thanks

### 1/5 — So where is the Apple Watch app

*2017-01-26, version 4.7*

I paid to use it in my watch since you are displaying a sample. It is not working or downloaded to my watch. So I need a refund or get a working app.

### 1/5 — Misleading

*2017-01-08, version 4.7*

This is made to look like a watch face for your Apple Watch it is nothing of the kind it is just a glorified stopwatch on your iphone or iPad and then they put an app on the I watch so that you can watch the seconds and milliseconds countdown a total scam!!

## Frequently asked questions about Atomic Clock

### What does the Atomic Clock app do?

The Atomic Clock app provides an ultra-precise, millisecond-accurate mobile clock. It syncs with a network of time reference servers to ensure the highest possible accuracy for your device's time display. It also shows the accuracy of your device in milliseconds.

### What are the key features of this app?

Key features include accuracy down to 1 millisecond (with subscription), syncing to multiple time reference servers, continuous auto-syncing, a Pulse Per Second (PPS) signal, and multiple alarm sounds with multi-time zone support. It also includes an up-to-date time zone table.

### Is this app free to use?

The app offers a freemium model. Some features, like accuracy down to 5 centiseconds and syncing to one server, are available for free. Enhanced features, such as 1-millisecond accuracy, displaying the device clock, and showing time differences, require a subscription.

### What devices is this app compatible with?

The application is available for mobile devices and also includes a FREE Apple Watch app. Specific operating system version requirements are not detailed in the provided description.

### Who would benefit from using this app?

This app is ideal for users who need highly accurate timekeeping, such as professionals in fields requiring precise timing, hobbyists, or anyone who wants to ensure their mobile device displays the most accurate time possible, including different time zones and specialized time formats.

## Version history (last 1 release)

### 4.7 — 2019-02-01

This app has been updated by Apple to display the Apple Watch app icon.

-Updates for overall speed improvement (Swift 3)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*