Comparison

Emerald Chronometer vs Atomic Clock

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

Head to head
About

Emerald Chronometer

Experience highly detailed mechanical watch faces with advanced astronomical and clock complications. Track celestial events, manage time with precision, and explore historical and future dates with interactive displays. Optimized for iPhone and iPod touch.

Highlights
  • Accurate astronomical data (4000 BCE - 2800 CE)
  • Sun, Moon, and planet rise/set times
  • Mechanical display of Moon phases
  • Precise local and UTC time
  • Chronograph with split timer
  • World-time and calendar watches
  • Interactive time-travel simulation
Read full description

These models of high-end mechanical watch faces contain many of the most complex "complications" found in real watches, plus refinements found nowhere else. All displays maintain the look and feel of real mechanical objects, but with the time and location accuracy of the iPhone. NOTE: This app (Emerald Chronometer) is optimized for the iPhone and iPod touch. Please also see Emerald Chronometer HD, a separate product optimized for the iPad. Astronomy features: - Highly accurate data from 4000 BCE to 2800 CE - Times of rise and set for the Sun, the Moon, and the 5 classical planets - The correct shape and orientation of the Moon in all phases but still using a mechanical display - Relative positions of the Sun, Moon, 6 planets and the constellations of the zodiac - "Compass functions" show the elevation and azimuth of the Sun, the Moon, and the 5 planets - The Equation of Time, solar time and sidereal time - Eclipse predictor (lunar node indicators and separation indicator) - User settable geographic location and timezone using an 80,000 city database - A unique face showing the rise and set times of all 5 classical planets plus the Sun and the Moon at once Clock features: - Day/date/month/year indicators, using mechanical wheels - Local and UTC time - Chronograph (stopwatch) with split timer, 1/10 sec accuracy - Alarm clock and interval timer; notifications are delivered in iOS 4 if the app is not running** - World-time watch with 24-city ring on one side and 4 subdials on the other - Calendar watch with rotating wheels showing a full month at a time - Most watches with 1/5 sec or 1/10 sec precision - Synchronized with standard atomic clocks via NTP There are 16 watches in all, with 27 total watch faces (including front and back sides). A setting is available to allow the display to stay on only when plugged in. Play with the watches by tapping on the crown and moving the hands, or press and hold on a date window to zoom through time to see the effect on the heavens. Then just use them to show you when it's time for a break. A complete description of each application feature can be found in the built-in Help screens and on the Emerald Sequoia LLC Web Site, which also includes a demo movie. A developer's blog may also be found at http://emeraldsequoia.com/esblog/ . If you are having any trouble with the application whatsoever, please see our FAQ on the support page listed below and then contact us through that page if your problem is not resolved. We take pride in responding promptly to all support email requests. **NTP accuracy is not guaranteed for alarm delivery if the app is not running. (NTP requires Internet access. Like all apps Emerald Chronometer can not change the device's internal clock.)

About

Atomic Clock

This app provides ultra-accurate time by synchronizing with global atomic clock servers. It offers a precise time display suitable for professionals, travelers, and anyone needing absolute accuracy. Features include real-time sync, customizable display options, and a minimalist interface.

Highlights
  • Real-time synchronization with atomic clock servers
  • 24-hour and 12-hour display
  • Minimalist clock face with dark mode
  • Offline functionality with last known time
  • Precise time down to the millisecond
Features
Read full description

Always know the exact time with Atomic Clock – Precise Time. Our app synchronizes with official atomic time servers to deliver ultra-accurate time down to the millisecond. Whether you’re coordinating across time zones, managing scientific experiments, or simply want the most reliable clock, this app provides unmatched precision. Features: - Real-time synchronization with global atomic clock servers - 24-hour and 12-hour display options - Beautiful, minimal clock face with dark mode - Works online and offline with last known atomic time - Perfect for professionals, travelers, pilots, scientists, and anyone who values absolute accuracy. An atomic clock is a timekeeping device that measures time based on the vibrations or transitions of atoms—usually cesium or rubidium. Unlike mechanical or quartz clocks, which rely on moving parts or crystals, atomic clocks use the natural oscillations of atoms as their frequency standard. This makes them the most accurate clocks ever developed, capable of maintaining time to within a few billionths of a second per day. Atomic clocks are essential for applications where extreme precision is required, such as GPS navigation, telecommunications, space exploration, scientific experiments, and synchronizing global networks.

Screenshots

Emerald Chronometer4 screens
Atomic Clock3 screens

Verdict

The call

The clearest difference is rating: Emerald Chronometer at 4.9 against Atomic Clock's 3.0. Emerald Chronometer also leads on ratings volume (122 vs 2). Atomic Clock's advantage is monetization model (free vs paid). On price, in-app purchases, 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Emerald Chronometer holds the better App Store score, 4.9 against 3.0. That said, the two scores are not equally well evidenced: Emerald Chronometer has 122 ratings behind it against 2, so its average is the more settled of the two.

Scorecard3 real differences · 7 level
Emerald Chronometer versus Atomic Clock: the parameters behind the verdict, then further details
ParameterEmerald ChronometerAtomic Clock
PriceFreeFree
Rating4.9 (122 ratings) — better3.0 (2 ratings)
Positive reviews96.8% of reviews—
Number of ratings122 — better2
Update frequencyEvery 22 months—
Ads—No
In-app purchasesNoNo
MonetizationPaidFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.0 — better15.1
Further details — not scored
Size311 MB29 MB
Age rating4+4+
DeveloperScapa Flow, LLCSTAN I. C. ALEXANDRU PERSOANA FIZICA AUTORIZATA

In-app purchases

None

Emerald Chronometer

No in-app purchases

None

Atomic Clock

No in-app purchases

Questions

Is Emerald Chronometer free?
Emerald Chronometer is free to download, with no in-app purchases.
Is Atomic Clock free?
Atomic Clock is free to download, with no in-app purchases.
Which has better reviews, Emerald Chronometer or Atomic Clock?
Emerald Chronometer is rated higher. Emerald Chronometer averages 4.9 out of 5 from 122 ratings, while Atomic Clock averages 3.0 from 2 ratings.

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