Comparison

AtomicClock vs GMT Time

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

GMT Time

This app provides accurate GMT time using NTP protocol and TrueTime framework. It offers a timekeeping function, allows setting time between two locations for itineraries, and supports multiple languages. Enjoy precise timekeeping with 1/100 second accuracy.

Highlights
  • Accurate GMT time display
  • NTP and TrueTime framework integration
  • Timekeeping function (on/off)
  • Set time between two locations
  • Multi-language support (English, Japanese, Chinese, Cantonese)
  • 1/100 second accuracy
Features
Read full description

Based on NTP (Network Time Protocol) protocol and TrueTime framework Get the correct GMT time anytime, anywhere on your mobile phone for free • Timekeeping function that can be turned on and off at any time • Set time between two places to facilitate business and travel itineraries • Provide timekeeping in English Japanese ,Chinese and Cantonese • NTP+ network delay calibration with 1/100 second accuracy

Screenshots

AtomicClock4 screens
GMT Time4 screens

Verdict

The call

The clearest difference is in-app purchases: GMT Time at none against AtomicClock's 1. AtomicClock's advantage is ratings volume (5.5K vs 37). On price, rating, ads 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. AtomicClock sells 1 one-off in-app purchase. GMT Time asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for AtomicClock against 4.7 for GMT Time. That said, the two scores are not equally well evidenced: AtomicClock has 5.5K ratings behind it against 37, so its average is the more settled of the two.

Scorecard3 real differences · 7 level
AtomicClock versus GMT Time: the parameters behind the verdict, then further details
ParameterAtomicClockGMT Time
PriceFreeFree
Rating4.8 (5.5K ratings) — better4.7 (37 ratings)
Positive reviews84.5% of reviews—
Number of ratings5.5K — better37
Update frequencyEvery 3 weeks—
AdsYesYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesAd-supported — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.014.0 — better
Further details — not scored
Size17 MB10 MB
Age rating4+4+
DeveloperTimo PartlMingChun Chien

Customer experience

AtomicClock

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

GMT Time

All ratings37 ratings
Positive89.2%
Neutral8.1%
Negative2.7%

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

GMT Time

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

AtomicClock

One-time1
  • Lifetime Pro Version$6.99
None

GMT Time

No in-app purchases

Questions

Is AtomicClock free?
AtomicClock is free to download, with in-app purchases available.
Is GMT Time free?
GMT Time is free to download, with no in-app purchases.
Which has better reviews, AtomicClock or GMT Time?
AtomicClock is rated higher. AtomicClock averages 4.8 out of 5 from 5.5K ratings, while GMT Time averages 4.7 from 37 ratings.
Do AtomicClock or GMT Time have ads?
Both AtomicClock and GMT Time show ads.

Other comparisons