# Emerald Chronometer

> Mechanical watch simulator with advanced astronomical and clock complications. (iPhone/iPad app by Scapa Flow, LLC.)

- Source: https://appshunter.io/ios/app/emerald-chronometer/id284953670 (this page in markdown: same URL + `.md`)
- Developer: [Scapa Flow, LLC](https://appshunter.io/developer/635350184)
- Category: Utilities, Entertainment
- Price: Free
- Rating: 4.90/5 from 105 App Store ratings · 63 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.0 · 311 MB
- Languages: English
- Released: 2019-02-01
- Data updated: 2026-08-25
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/emerald-chronometer/id284953670/reviews.md

## What is Emerald Chronometer?

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.)

## Key features

- 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

## Recent user reviews (10 of 63)

All indexed reviews: https://appshunter.io/ios/app/emerald-chronometer/id284953670/reviews.md

### 5/5 — It’s Back! and beautiful!

*2026-05-06*

The new release of Emerald Chronometer is faithful to the original that had its support dropped in 2023. The chronometers are beautiful and the complications are great! Get it! You will be glad you did.

### 5/5 — It's back! ^.^

*2026-05-06*

What a pleasant surprise! I have stubbornly  hung on to this app, even though it had been officially discontinued, as long as I don't delete it, it would make it to my new phone and I could enjoy it functionality and elegance. And here it is, acquired, by all portents, by  another artist as in love with the concept, but obviously, also a capable programmer who will bring it up to current OS expectations! I'm overjoyed! Thank you! ^.^

### 5/5 — Sad day today

*2023-12-15*

Really wish this app wasn’t going away. I guess I missed my opportunity to get a replacement iPad so I could have Obsevatory again. 
Is there any chance that this would be available elsewhere, to install on a jail broken device?

This breaks my heart.

These were the best apps ever available for iOS — these and the IK Multimedia music apps. 

You guys are the best. Hate to lose you.

### 5/5 — What a gift!

*2023-10-28*

So sorry to see the app ending. I have enjoyed this app so much since it came out, and learned much about time, time keeping, design, astronomy, history. What a joy it has been.  Hands down the best iPhone app I’ve ever purchased. I will retire my current iPhone with no further operating system updates in hopes of preserving Chronometer for awhile longer. 
Thank you for all  the work (joy, love) you’ve put into it over the years.

### 5/5 — Thanks and farewell

*2023-10-24*

Again, many thanks for all the many watch faces.

### 5/5 — Farewell

*2023-09-28*

I’m so sad this app is closing down. When I was 12 (47 years ago) for Christmas my father gave me a Timex self-winding watch just like the one he wore to work where he worked on the rockets that first landed men on the moon. During P.E. at school someone broke into my locker and stole my watch. I’ve prayed for 47 years for the miracle of finding it. The Chronometer App has the closest thing I ever found that looks like that watch so I purchased the app. I’m ready to pay any reasonable amount for the Chronometer App compiled to run on a Windows PC platform. Developers: If there is even a remote possibility of that happening, please email me. If not, goodbye and thank you for the time the app was available. Best wishes.

### 5/5 — The Best of all.

*2023-09-18*

This app is used by professionals (both government and private), for Apple to incorporate this into their iOS would be life changing.

### 5/5 — I don’t want to see you go

*2023-09-11*

I’ve had this app on each of my iPhones since the app was first released 

I’ll keep using it until I can’t anymore 

Good luck to you all 🙏🏼

### 5/5 — Sad to see Emerald Go

*2023-09-05*

This venerable clock app is one of the first 3rd party apps I installed way back when the App Store was just getting going and long before the Apple Watch.  It still holds up very well with solid graphics and creative faces.   Time is constant but times change and sad to see the developer moving on.  Will continue to use the app as long as it’s possible.

### 5/5 — Farewell, friends

*2023-09-05*

Sorry to hear about your shutting the app down, but you provided a wonderful product all these years. I pray for you all the luck in what life brings your way. 👍🏽

## Frequently asked questions about Emerald Chronometer

### What does Emerald Chronometer do?

Emerald Chronometer provides highly detailed simulations of high-end mechanical watch faces. These watches feature complex 'complications' such as astronomical tracking for the Sun, Moon, and planets, as well as precise clock functions like chronographs and world time displays. The app aims to replicate the look and feel of real mechanical objects while leveraging the accuracy of your iPhone.

### What are the key features of Emerald Chronometer?

Key features include highly accurate astronomical data spanning from 4000 BCE to 2800 CE, with times for rise and set of celestial bodies. It offers mechanical displays for Moon phases, relative planetary positions, and compass functions. Clock features include precise local and UTC time, a chronograph with split timer, an alarm clock, and world-time and calendar watches.

### How much does Emerald Chronometer cost?

Emerald Chronometer is a paid application. The price is a one-time purchase, and there are no in-app purchases or subscriptions mentioned for this product. Please check the app store for the current pricing.

### What devices is Emerald Chronometer compatible with?

This version of Emerald Chronometer is optimized for the iPhone and iPod touch. A separate product, Emerald Chronometer HD, is available and optimized for the iPad. The app requires iOS 4 or later for certain notification features.

### How can I use Emerald Chronometer for common use cases?

Users can use Emerald Chronometer to explore detailed astronomical events, such as predicting eclipses or tracking the positions of planets. It also serves as a sophisticated timekeeping tool with its chronograph and world-time functions. The interactive nature allows users to 'zoom through time' to observe celestial changes, making it useful for educational purposes or simply appreciating the complexity of mechanical watchmaking.

## Version history (last 4 releases)

### 4.1 — 2026-05-05

Optimized for iOS 26, this version has the same original watch faces.

### 3.12.2 — 2023-10-23

* Built against latest development SDK
* Includes some watches from the developers' workbench

### 3.11.1 — 2023-09-04

Warning about company shutdown

### 3.10.1 — 2021-11-07

- Support for Dark Mode
- Support for iOS 15

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| --- | --- | --- | --- |
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## More apps by Scapa Flow, LLC

- [MonthlyPaymentCalc](https://appshunter.io/ios/app/monthlypaymentcalc/id635350181)
- [Repertoire](https://appshunter.io/ios/app/repertoire/id1049812919)
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- [Colorado Institute of Music](https://appshunter.io/ios/app/colorado-institute-of-music/id1431579693)

All apps by Scapa Flow, LLC: https://appshunter.io/developer/635350184

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-25.*