AtomicClock vs GMT Time
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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.
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.
- 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
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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
Verdict
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
Both are free to download. AtomicClock sells 1 one-off in-app purchase. GMT Time asks for nothing beyond the download.
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.
| Parameter | AtomicClock | GMT Time |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (5.5K ratings) — better | 4.7 (37 ratings) |
| Positive reviews | 84.5% of reviews | — |
| Number of ratings | 5.5K — better | 37 |
| Update frequency | Every 3 weeks | — |
| Ads | Yes | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Ad-supported — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 14.0 — better |
| Further details — not scored | ||
| Size | 17 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Timo Partl | MingChun Chien |
Customer experience
AtomicClock
GMT Time
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
AtomicClock
- Lifetime Pro Version$6.99
GMT Time
No in-app purchases









