# Emerald Chronometer vs SynScan Pro

The clearest difference is review sentiment: Emerald Chronometer at 97% against SynScan Pro's 22%. Emerald Chronometer also leads on rating (4.9 vs 2.6). SynScan Pro's advantage is update cadence (every 2 months vs every 22 months). On price, ratings volume, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Emerald Chronometer holds the better App Store score, 4.9 against 2.6. Both are backed by a comparable volume of ratings — 105 and 51 respectively. Written reviews point the same way: 97% of Emerald Chronometer's written reviews are positive against 22% of SynScan Pro's.

Emerald Chronometer ships an update every 22 months, SynScan Pro every 2 months. The most recent releases landed on October 6, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Emerald Chronometer | SynScan Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (105 ratings)](https://appshunter.io/ios/app/emerald-chronometer/id284953670/reviews)** | [2.6 (51 ratings)](https://appshunter.io/ios/app/synscan-pro/id1302270121/reviews) |
| Number of ratings | **105** | 51 |
| Positive reviews | **96.8% of reviews** | 21.5% of reviews |
| In-app purchases | No | No |
| Ads | — | No |
| Update frequency | Every 22 months | **Every 2 months** |
| Monetization | Paid | Paid |
| Size | 311 MB | 46 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Scapa Flow, LLC](https://appshunter.io/developer/635350184) | [Astropower Technology Co. Ltd.](https://appshunter.io/developer/1787940478) |

## What reviewers say

### Emerald Chronometer

[App page](https://appshunter.io/ios/app/emerald-chronometer/id284953670)

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

**In-app purchases:** none


### SynScan Pro

[App page](https://appshunter.io/ios/app/synscan-pro/id1302270121)

Control motorized telescope mounts for celestial observation and astrophotography. Features include precise slewing, alignment, GOTO, and tracking of stars, planets, and deep-sky objects. Supports advanced functions like polar alignment and camera triggering.

**Highlights:** Control telescope mount (slew, align, GOTO, track), Point and Track celestial objects, Gamepad navigation support, Catalog of celestial objects, Third-party app integration (ASCOM, SkySafari), Polar alignment (with or without polar scope), Camera shutter release control

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Emerald Chronometer free?

Emerald Chronometer is free to download, with no in-app purchases.

### Is SynScan Pro free?

SynScan Pro is free to download, with no in-app purchases.

### Which has better reviews, Emerald Chronometer or SynScan Pro?

Emerald Chronometer is rated higher. Emerald Chronometer averages 4.9 out of 5 from 105 ratings, while SynScan Pro averages 2.6 from 51 ratings.

### Which is updated more often, Emerald Chronometer or SynScan Pro?

Emerald Chronometer ships an update every 22 months, and SynScan Pro every 2 months. Most recently, Emerald Chronometer was updated on October 6, 2026 and SynScan Pro on October 9, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*