# Emerald Observatory for iPad vs Visolve RT for iPhone

The clearest difference is monetization model: Visolve RT for iPhone at free against Emerald Observatory for iPad's paid. Visolve RT for iPhone also leads on device support (3 vs 1) and iOS requirement (11.0 vs 17.0). Emerald Observatory for iPad's advantage is update cadence (every 5 months vs every 13 months). On price, review sentiment, ads and in-app purchases 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 ships an update every 5 months, Visolve RT for iPhone every 13 months. The most recent releases landed on November 1, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Emerald Observatory for iPad | Visolve RT for iPhone |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (99 ratings)](https://appshunter.io/ios/app/emerald-observatory-for-ipad/id364904759/reviews)** | — |
| Number of ratings | **99** | — |
| Positive reviews | 98.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 13 months |
| Monetization | Paid | **Free** |
| Size | 19 MB | 3 MB |
| Requires iOS | 17.0 | **11.0** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Bjorn Freeman-Benson](https://appshunter.io/developer/1766829089) | [Ryobi Systems Co.,Ltd.](https://appshunter.io/developer/422237051) |

## 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


### Visolve RT for iPhone

[App page](https://appshunter.io/ios/app/visolve-rt-for-iphone/id668502747)

This utility app assists individuals with color vision deficiency by applying real-time video transformations to enhance color perception. It offers various filters and simulations to help users distinguish colors, find specific hues, or understand how others perceive the world.

**Highlights:** Real-time video color transformations, Red-Green color transform, Blue-Yellow color transform, Saturation increase, Color filtering, Hatching patterns, Color blindness simulation

**Features:** macOS Compatibility

**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 Visolve RT for iPhone free?

Visolve RT for iPhone is free to download, with no in-app purchases.

### Do Emerald Observatory for iPad or Visolve RT for iPhone have ads?

Neither Emerald Observatory for iPad nor Visolve RT for iPhone shows ads.

### Which is updated more often, Emerald Observatory for iPad or Visolve RT for iPhone?

Emerald Observatory for iPad ships an update every 5 months, and Visolve RT for iPhone every 13 months. Most recently, Emerald Observatory for iPad was updated on November 1, 2026 and Visolve RT for iPhone 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.*