Comparison

Time Calibrator vs AtomicClock

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

Head to head
About

Time Calibrator

This utility app provides precise local time and date information by connecting to an atomic clock server in Switzerland. It utilizes quantum technology to transmit this data at the speed of light directly to compatible i-Atomic watches.

Highlights
  • Accurate global time and date
  • Connects to Swiss atomic clock server
  • Quantum technology data transmission
  • Direct communication to i-Atomic watches
  • Light signal synchronization
Features
Read full description

This app is designed for i-Atomic watches users Welcome to Time Calibrator! Time Calibrator has been specifically designed to deliver accurate time information to people all around the globe. The app connects automatically to the atomic clock server in Switzerland to display the exact local time and date. Through quantum technology, the information travels at the speed of light from the NTP server and is communicated directly to AtomTime i-Atomic watches via light signals.

About

AtomicClock

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
Read full description

Check precise NTP reference time at a glance. AtomicClock helps you set watches, wall clocks, cameras, and other devices, compare local time with UTC, and follow moments when every second matters. Clear analog and digital time AtomicClock displays current time from NTP servers that reference atomic clocks. Choose a predefined server or add your own, then view local or UTC time in a clean analog or digital clock. Customize your reference clock • Switch between 12-hour and 24-hour time • Customize the time format • Choose from multiple clock faces and hands • Use a smooth, fluid second hand • Add acoustic ticking or the Greenwich Time Signal • Tap the screen to hide information and controls, freeze the display, or mute ticking Details for precise time checks View technical NTP information, including round-trip time and server stratum. Whether you are checking a timestamp, preparing a camera, aligning a wall clock, or setting a watch by hand, the seconds remain clear and easy to follow. AtomicClock is free to use. AtomicClock Pro is available as a one-time purchase with no subscription. It unlocks your preferred clock face, hands, and font, removes ads, and includes upcoming Pro features. AtomicClock displays NTP reference time for comparison and does not change your device’s system time. Results can vary with the selected server, network conditions, and device behavior.

Screenshots

Time Calibrator3 screens
AtomicClock4 screens

Verdict

The call

The clearest difference is review sentiment: AtomicClock at 85% against Time Calibrator's 33%. AtomicClock also leads on rating (4.8 vs 2.7) and update cadence (every 3 weeks vs every 8 months). Time Calibrator's advantage is in-app purchases (none vs 1) and ads (none vs shown). On price, device support and iOS requirement 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. AtomicClock sells 1 one-off in-app purchase. Time Calibrator asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

AtomicClock holds the better App Store score, 4.8 against 2.7. That said, the two scores are not equally well evidenced: AtomicClock has 5.5K ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 33% of Time Calibrator's written reviews are positive against 85% of AtomicClock's.

UpkeepUpdate frequency

Time Calibrator ships an update every 8 months, AtomicClock every 3 weeks. The most recent releases landed on August 24, 2026 and September 24, 2026 respectively.

Scorecard7 real differences · 3 level
Time Calibrator versus AtomicClock: the parameters behind the verdict, then further details
ParameterTime CalibratorAtomicClock
PriceFreeFree
Rating2.7 (3 ratings)4.8 (5.5K ratings) — better
Positive reviews33.3% of reviews84.5% of reviews — better
Number of ratings35.5K — better
Update frequencyEvery 8 monthsEvery 3 weeks — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.615.0 — better
Further details — not scored
Size8 MB17 MB
Age rating4+4+
DeveloperAtomtime Suisse S.A.Timo Partl

Customer experience

Time Calibrator

All ratings3 ratings
Positive33.3%
Neutral0.0%
Negative66.7%
Written reviews3 reviews
Positive33.3%
Neutral0.0%
Negative66.7%

AtomicClock

All ratings5,539 ratings
Positive96.5%
Neutral1.8%
Negative1.8%
Written reviews239 reviews
Positive84.5%
Neutral3.3%
Negative12.1%

Bugs and requests

Time Calibrator

Not enough reviews yet to summarise bugs or requests.

AtomicClock

Reported bugs

3 issues
  • Crashes on certain iOS versions
  • Occasional freezing of hands
  • Countdown timer sound not working

Requested features

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

In-app purchases

None

Time Calibrator

No in-app purchases

1 purchases

AtomicClock

One-time1
  • Lifetime Pro Version$6.99

Questions

Is Time Calibrator free?
Time Calibrator is free to download, with no in-app purchases.
Is AtomicClock free?
AtomicClock is free to download, with in-app purchases available.
Which has better reviews, Time Calibrator or AtomicClock?
AtomicClock is rated higher. Time Calibrator averages 2.7 out of 5 from 3 ratings, while AtomicClock averages 4.8 from 5.5K ratings.
Do Time Calibrator or AtomicClock have ads?
AtomicClock shows ads; Time Calibrator does not.
Which is updated more often, Time Calibrator or AtomicClock?
Time Calibrator ships an update every 8 months, and AtomicClock every 3 weeks. Most recently, Time Calibrator was updated on August 24, 2026 and AtomicClock on September 24, 2026.

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