Time Calibrator vs AtomicClock
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Accurate global time and date
- Connects to Swiss atomic clock server
- Quantum technology data transmission
- Direct communication to i-Atomic watches
- Light signal synchronization
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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.
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.
Screenshots
Verdict
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
Both are free to download. AtomicClock sells 1 one-off in-app purchase. Time Calibrator asks for nothing beyond the download.
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.
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.
| Parameter | Time Calibrator | AtomicClock |
|---|---|---|
| Price | Free | Free |
| Rating | 2.7 (3 ratings) | 4.8 (5.5K ratings) — better |
| Positive reviews | 33.3% of reviews | 84.5% of reviews — better |
| Number of ratings | 3 | 5.5K — better |
| Update frequency | Every 8 months | Every 3 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 8 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Atomtime Suisse S.A. | Timo Partl |
Customer experience
Time Calibrator
AtomicClock
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
Time Calibrator
No in-app purchases
AtomicClock
- Lifetime Pro Version$6.99
Questions
Is Time Calibrator free?
Is AtomicClock free?
Which has better reviews, Time Calibrator or AtomicClock?
Do Time Calibrator or AtomicClock have ads?
Which is updated more often, Time Calibrator or AtomicClock?
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