# Emerald Observatory for iPad vs LSTclock

The clearest difference is review sentiment: Emerald Observatory for iPad at 99% against LSTclock's 55%. Emerald Observatory for iPad also leads on rating (4.9 vs 3.8) and ratings volume (84 vs 10). LSTclock's advantage is monetization model (free vs paid) and update cadence (every 2 months vs every 5 months). On price, ads, in-app purchases and iOS requirement there is nothing between them.

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

Emerald Observatory for iPad holds the better App Store score, 4.9 against 3.8. That said, the two scores are not equally well evidenced: Emerald Observatory for iPad has 84 ratings behind it against 10, so its average is the more settled of the two. Written reviews point the same way: 99% of Emerald Observatory for iPad's written reviews are positive against 55% of LSTclock's.

Emerald Observatory for iPad ships an update every 5 months, LSTclock every 2 months. The most recent releases landed on September 25, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Emerald Observatory for iPad | LSTclock |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (84 ratings)](https://appshunter.io/ios/app/emerald-observatory-for-ipad/id364904759/reviews)** | [3.8 (10 ratings)](https://appshunter.io/ios/app/lstclock-sidereal-time-clock/id1510148631/reviews) |
| Number of ratings | **84** | 10 |
| Positive reviews | **98.6% of reviews** | 54.5% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Size | 16 MB | 15 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Bjorn Freeman-Benson](https://appshunter.io/developer/1766829089) | [Tsuyoshi Sawada](https://appshunter.io/developer/1510148630) |

## What reviewers say

### Emerald Observatory for iPad

[App page](https://appshunter.io/ios/app/emerald-observatory-for-ipad/id364904759)

This app provides a comprehensive astronomical display on a single screen, offering detailed information about celestial bodies and timekeeping. It features a heliocentric orrery, rise and set times, twilight information, and moon phase details. Users can navigate through time and set alarms for astronomical events.

**Highlights:** Astronomical information display, Heliocentric orrery, Rise and set times for Sun, Moon, planets, Twilight times, Moon phase and orientation, World map of day/night regions, Eclipse simulator

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- ✨ Visually stunning and beautiful design
- 💡 Extremely informative and data-rich
- 👍 Elegant and exquisite user interface
- 🚀 Flawless UX and intuitive design
- 🌟 Unique and nonpareil functionality

**What reviewers complain about**

- ⏳ Last update a year ago
- 🤔 Interface can be tough to decipher initially
- 🔄 Lack of recent updates
- 📱 Not available on iPhone/Apple Watch

**Requested features**

- Port to screen wallpaper
- Large wall clock version
- Apple TV version
- Support for Uranus, Neptune, and Pluto
- iPhone and Apple Watch versions


### LSTclock

[App page](https://appshunter.io/ios/app/lstclock-sidereal-time-clock/id1510148631)

This utility app displays local sidereal time for registered locations on iOS, iPadOS, and watchOS. It can also calculate sidereal time and Julian Date for any date and time, and sync locations between devices.

**Highlights:** Local sidereal time display, Julian Date calculation, Supports multiple registered locations, Location sync between iPhone and Apple Watch, Date and time specific calculations

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Emerald Observatory for iPad free?

Emerald Observatory for iPad is free to download, with no in-app purchases.

### Is LSTclock free?

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

### Which has better reviews, Emerald Observatory for iPad or LSTclock?

Emerald Observatory for iPad is rated higher. Emerald Observatory for iPad averages 4.9 out of 5 from 84 ratings, while LSTclock averages 3.8 from 10 ratings.

### Do Emerald Observatory for iPad or LSTclock have ads?

Neither Emerald Observatory for iPad nor LSTclock shows ads.

### Which is updated more often, Emerald Observatory for iPad or LSTclock?

Emerald Observatory for iPad ships an update every 5 months, and LSTclock every 2 months. Most recently, Emerald Observatory for iPad was updated on September 25, 2026 and LSTclock on September 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.*