Comparison

AtomicClock vs Cool Ukiyo

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

Head to head
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.

About

Cool Ukiyo

Features
Read full description

This is a digital and analog clock with a background of famous Ukiyo-e prints. You can choose from 40 different Ukiyo-e works from various periods. The time, analog clock, and Ukiyo-e can be moved with a finger. The analog clock and Ukiyo-e can be zoomed in and out with two fingers. Seconds can also be displayed. The background color can be selected from 5 different colors. Touching the time character switches to setting mode. When in setting mode, you can change the year, month, and day of the week to various formats by touching. The year, month, day of the week, a.m./p.m., and seconds can be erased. You can also switch between 12-hour and 24-hour displays. Rotation of the screen in portrait and landscape mode is also supported. The size of the text can be adjusted in steps by pressing buttons such as "2X" and "3X". The time signal can be selected from 78 different tones.

Screenshots

AtomicClock4 screens
Cool Ukiyo4 screens

Verdict

The call

The clearest difference is iOS requirement: Cool Ukiyo at 12.0 against AtomicClock's 15.0. On price, update cadence, ads and in-app purchases 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 and Cool Ukiyo sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

AtomicClock ships an update every 3 weeks, Cool Ukiyo monthly. The most recent releases landed on September 24, 2026 and September 9, 2026 respectively.

Scorecard1 real difference · 9 level
AtomicClock versus Cool Ukiyo: the parameters behind the verdict, then further details
ParameterAtomicClockCool Ukiyo
PriceFreeFree
Rating4.8 (5.5K ratings) — better—
Positive reviews84.5% of reviews—
Number of ratings5.5K — better—
Update frequencyEvery 3 weeks — betterMonthly
AdsYesYes
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.012.0 — better
Further details — not scored
Size17 MB53 MB
Age rating4+4+
DeveloperTimo PartlMihoko Araki

Bugs and 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

Cool Ukiyo

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

AtomicClock

One-time1
  • Lifetime Pro Version$6.99
1 purchases

Cool Ukiyo

One-time1
  • Cool Ukiyo-e Clock with no ads$3.99

Questions

Is AtomicClock free?
AtomicClock is free to download, with in-app purchases available.
Is Cool Ukiyo free?
Cool Ukiyo is free to download, with in-app purchases available.
Do AtomicClock or Cool Ukiyo have ads?
Both AtomicClock and Cool Ukiyo show ads.
Which is updated more often, AtomicClock or Cool Ukiyo?
AtomicClock ships an update every 3 weeks, and Cool Ukiyo monthly. Most recently, AtomicClock was updated on September 24, 2026 and Cool Ukiyo on September 9, 2026.

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