Comparison

Emerald Chronometer vs SmartwatchCenter

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

SmartwatchCenter

Features
Read full description

SmartwatchCenter — Custom Watch Faces & Dials Give your smartwatch a fresh look. SmartwatchCenter is an independent gallery of original watch-face designs created by our own team — browse, preview, and install a new face in seconds. Original designs, made by us - Watch faces designed and built in-house by the SmartwatchCenter team - Digital, analog, minimalist, fitness, chronograph, elegant and more - Fast search and category filters to find the perfect look - Save your favorites and revisit them anytime - Designs are matched to your watch model, so previews look exactly right Simple, safe installation SmartwatchCenter does not connect to or control your watch. To install a face, the app creates a standard QR code. You then scan it with the official Zepp app using its built-in Developer Mode — the official app performs the installation. Nothing is modified on your device beyond adding the watch face you chose. A step-by-step in-app guide walks you through enabling Developer Mode (a one-time setup) and scanning the code. Compatibility SmartwatchCenter is designed for a wide range of compatible smartwatches. Any model names shown in the app are used only to help you identify your own device. Free to use SmartwatchCenter is free and supported by ads. An optional Premium upgrade removes ads and unlocks extra convenience. No account or login is required. Premium (optional) SmartwatchCenter Premium is an auto-renewable subscription that removes ads and unlocks extra convenience. - Monthly and Yearly plans (a one-time Lifetime option is also available). - Price is shown in the app before purchase, in your local currency. - Payment is charged to your Apple Account at confirmation of purchase. - The subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours prior to the end of the current period. - You can manage or cancel your subscription in your Apple Account settings after purchase. Any unused portion of a free trial (if offered) is forfeited when purchasing a subscription. --- Disclaimer SmartwatchCenter is an independent application. It is not affiliated with, endorsed by, or sponsored by Amazfit, Zepp Health, or Xiaomi. All product and brand names are trademarks of their respective owners and are used only to indicate device compatibility. All watch faces in the app are original works created by the SmartwatchCenter team. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://watchface-lab.web.app/privacy-policy.html

Screenshots

Emerald Chronometer4 screens
SmartwatchCenter4 screens

Verdict

The call

The clearest difference is in-app purchases: Emerald Chronometer at none against SmartwatchCenter's 3. Emerald Chronometer also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.0). SmartwatchCenter's advantage is update cadence (daily vs every 22 months). On price 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. SmartwatchCenter sells 3 in-app purchases, starting at $2.99 per month. Emerald Chronometer asks for nothing beyond the download.

UpkeepUpdate frequency

Emerald Chronometer ships an update every 22 months, SmartwatchCenter daily. Both last shipped on November 6, 2026.

Scorecard4 real differences · 6 level
Emerald Chronometer versus SmartwatchCenter: the parameters behind the verdict, then further details
ParameterEmerald ChronometerSmartwatchCenter
PriceFreeFree
Rating4.9 (122 ratings) — better—
Positive reviews96.8% of reviews—
Number of ratings122 — better—
Update frequencyEvery 22 monthsDaily — better
Ads—No
In-app purchasesNo — betterYes
MonetizationPaid—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.0 — better17.0
Further details — not scored
Size311 MB13 MB
Age rating4+4+
DeveloperScapa Flow, LLCKhang Tran

In-app purchases

None

Emerald Chronometer

No in-app purchases

3 purchases

SmartwatchCenter

Subscriptions2
  • Pro Monthly$2.991 Month
  • Pro Yearly$17.991 Year
One-time1
  • Pro Lifetime$39.99

Questions

Is Emerald Chronometer free?
Emerald Chronometer is free to download, with no in-app purchases.
Is SmartwatchCenter free?
SmartwatchCenter is free to download, with in-app purchases available.
Which is updated more often, Emerald Chronometer or SmartwatchCenter?
Emerald Chronometer ships an update every 22 months, and SmartwatchCenter daily. Most recently, Emerald Chronometer was updated on November 6, 2026 and SmartwatchCenter on November 6, 2026.

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