Comparison

Atomic Clock PRO vs Atomic Sync

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Atomic Clock PRO

This app provides highly accurate time by syncing with official atomic clock servers. Customize your display with digital or analog views, personal backgrounds, and adjustable sizes. It's perfect for precise timekeeping, travel, or as a personalized desk clock.

Highlights
  • Atomic clock time synchronization
  • Digital and analog display options
  • Customizable backgrounds
  • Adjustable clock size
  • Automatic time zone recognition
  • Screen always on option
Features
Read full description

Get accurate time on your iPhone and iPad by syncing with an official atomic clock time server. Download now for free! If you want exact time, a precise time reference, or an easy-to-read clock display, this app is designed for that. It automatically recognizes your time zone, lets you use one of your own photos as the background, and lets you switch between a digital display and a classic analog clock with a simple swipe. It is ideal as a personalized desk clock, a reliable travel companion, an everyday reference clock, or when you need exact time to set a mechanical watch accurately. Overview: - Accurate and precise time synced from an official atomic clock time server - Automatically recognizes your time zone and shows the current local time - Choose digital, analog, or combined analog and digital clock displays - Swipe to switch between clock displays - Resize the digital clock for a larger or smaller display - Includes time (hours, minutes, and seconds), date, and day of the week (optional) - Optional sound every second or every minute - Change clock and background colors - Use your own photos as background images - Choose atomic clock sync or your device's system clock - Option to keep the screen awake while the app is open - Works in portrait and landscape mode - For iPhone and iPad Helpful for: - A personalized desk clock at home or at work - Getting the correct local time while traveling - Setting a mechanical watch accurately - A clear reference clock when you want accurate, easy-to-read time PLEASE NOTE: You can switch between the analog and digital clock by swiping left or right across the clock. Disclaimer: Please note that whilst all reasonable care has been taken to make this application as accurate as possible we can not guarantee 100% accuracy. Standard Apple Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Atomic Sync

Synchronize your radio-controlled watch using your phone's speaker to emulate atomic time signals. Supports various international time signals and offers smart reminders for regular synchronization. Works offline and prioritizes user privacy.

Highlights
  • Emulates atomic time signals
  • Supports multiple international time signals
  • Offline synchronization
  • Smart reminders for syncing
  • User-friendly design with dark/light themes
  • Privacy-focused with no data collection
Features
Read full description

Sync Your Radio-Controlled Watch in Minutes! Atomic Sync emulates official atomic time signals to synchronize your radio-controlled watch — no tower reception needed. Works with Casio G-Shock, Citizen, Lacrosse, Junghans, Braun and other atomic watches. SUPPORTED TIME SIGNALS: • WWVB (60 kHz) — United States • DCF77 (77.5 kHz) — Germany / Europe • JJY40 / JJY60 (40/60 kHz) — Japan • MSF (60 kHz) — United Kingdom • BPC (68.5 kHz) — China • RBU (66.66 kHz) — Russia HOW IT WORKS: 1. Select your region or time signal 2. Place your phone near your watch (see visual guide) 3. Tap Start and wait 1-10 minutes 4. Your watch syncs to atomic time — done! BEAST MODE (Premium Sync): Need faster sync? Watch a short rewarded video to activate Beast Mode — our enhanced signal algorithm for quicker, more reliable synchronization. Unlimited use, no subscriptions. SMART REMINDERS: Set local notifications to remind you to sync your watch daily, weekly, bi-weekly, monthly or custom. Never lose atomic precision again. OFFLINE & ACCURATE: • All signals generated locally — no internet required for sync • Optional NTP time source sync for maximum accuracy when online • Last known time cached for offline use USER-FRIENDLY DESIGN: • Dark/Light theme (auto-switch) • Universal positioning guide with animated signal waves • Simple 4-step flow, no brand selection needed • 16 languages supported PRIVACY FIRST: • No location access required • No personal data collected • No account registration needed COMPATIBLE WITH: Casio G-Shock, Pro Trek, Edifice • Citizen Eco-Drive • Lacrosse Technology • Junghans Mega • Braun watches • And any watch supporting WWVB/DCF77/JJY/MSF/BPC signals. TIPS FOR SUCCESS: • Use maximum phone volume during sync • Keep phone and watch still, 2-10 cm apart • Avoid metal surfaces and electronic interference DISCLAIMER: Atomic Sync is a third-party tool and is not affiliated with, endorsed by, or connected to Casio, Citizen, or any watch manufacturer. Time signal emulation is for personal use only. Success depends on watch model, environment, and device hardware.

Screenshots

Atomic Clock PRO4 screens
Atomic Sync3 screens

Verdict

The call

The clearest difference is rating: Atomic Clock PRO at 4.7 against Atomic Sync's 2.5. Atomic Clock PRO also leads on ratings volume (10K vs 2). Atomic Sync's advantage is in-app purchases (none vs 2) and update cadence (fortnightly vs every 4 months). On price, ads, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

ReceptionRating · Positive reviews · Number of ratings

Atomic Clock PRO holds the better App Store score, 4.7 against 2.5. That said, the two scores are not equally well evidenced: Atomic Clock PRO has 10K ratings behind it against 2, so its average is the more settled of the two.

UpkeepUpdate frequency

Atomic Clock PRO ships an update every 4 months, Atomic Sync fortnightly. The most recent releases landed on November 8, 2026 and October 31, 2026 respectively.

Scorecard4 real differences · 6 level
Atomic Clock PRO versus Atomic Sync: the parameters behind the verdict, then further details
ParameterAtomic Clock PROAtomic Sync
PriceFreeFree
Rating4.7 (10K ratings) — better2.5 (2 ratings)
Positive reviews72.9% of reviews—
Number of ratings10K — better2
Update frequencyEvery 4 monthsFortnightly — better
AdsYesYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.615.0 — better
Further details — not scored
Size6 MB27 MB
Age rating4+4+
DeveloperBrachmann Online Marketing GmbH & Co. KGSerhii Sereda

Bugs and requests

Atomic Clock PRO

Reported bugs

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

Requested features

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

Atomic Sync

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

Atomic Clock PRO

Subscriptions1
  • Premium$1.991 Month
One-time1
  • Remove Ads$5.99
None

Atomic Sync

No in-app purchases

Questions

Is Atomic Clock PRO free?
Atomic Clock PRO is free to download, with in-app purchases available.
Is Atomic Sync free?
Atomic Sync is free to download, with no in-app purchases.
Which has better reviews, Atomic Clock PRO or Atomic Sync?
Atomic Clock PRO is rated higher. Atomic Clock PRO averages 4.7 out of 5 from 10K ratings, while Atomic Sync averages 2.5 from 2 ratings.
Do Atomic Clock PRO or Atomic Sync have ads?
Both Atomic Clock PRO and Atomic Sync show ads.
Which is updated more often, Atomic Clock PRO or Atomic Sync?
Atomic Clock PRO ships an update every 4 months, and Atomic Sync fortnightly. Most recently, Atomic Clock PRO was updated on November 8, 2026 and Atomic Sync on October 31, 2026.

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