# Monad Calendar Clock vs Solar System Viewer

The clearest difference is review sentiment: Solar System Viewer at 83% against Monad Calendar Clock's 22%. Solar System Viewer also leads on rating (4.4 vs 3.7). Monad Calendar Clock's advantage is in-app purchases (none vs 4) and chart position (#177 vs unranked). On ratings volume, update cadence, ads and monetization model there is nothing between them.

Monad Calendar Clock costs $0.99 and Solar System Viewer $2.99 up front. Solar System Viewer sells 4 one-off in-app purchases. Monad Calendar Clock asks for nothing beyond the download.

Solar System Viewer holds the better App Store score, 4.4 against 3.7. Both are backed by a comparable volume of ratings — 14 and 28 respectively. Written reviews point the same way: 22% of Monad Calendar Clock's written reviews are positive against 83% of Solar System Viewer's.

Monad Calendar Clock ships an update every 6 weeks, Solar System Viewer every 2 months. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Monad Calendar Clock | Solar System Viewer |
| --- | --- | --- |
| Price | **$0.99** | $2.99 |
| Rating | [3.7 (14 ratings)](https://appshunter.io/ios/app/monad-calendar-clock/id1437026437/reviews) | **[4.4 (28 ratings)](https://appshunter.io/ios/app/solar-system-viewer-8planets/id1554639445/reviews)** |
| Number of ratings | 14 | **28** |
| Positive reviews | 22.2% of reviews | **83.3% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 2 months |
| Monetization | Paid | Paid |
| Best chart rank | **#177** | — |
| Size | 266 MB | 22 MB |
| Requires iOS | **13.0** | 26.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, Mac, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Earth at the Center LLC](https://appshunter.io/developer/1437026436) | [BLUE COMET LABS LLC](https://appshunter.io/developer/1492055170) |

## What reviewers say

### Monad Calendar Clock

[App page](https://appshunter.io/ios/app/monad-calendar-clock/id1437026437)

**Currently charting:** #177 Top Paid · Education (US App Store)

This app visualizes time through planetary and celestial movements, contrasting natural rhythms with mechanical time. It offers unique perspectives on Earth's position in space and time, showing star and planet locations, seasonal changes, and lunar phases.

**Highlights:** Planetary time and date display, Celestial ring visualization, Heliocentric and Geocentric modes, Star and planet location tracking, Seasonal and lunar phase progression, Twilight and sunrise/sunset times, Event scheduling

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

**In-app purchases:** none


### Solar System Viewer

[App page](https://appshunter.io/ios/app/solar-system-viewer-8planets/id1554639445)

Explore and simulate the orbits of planets in our solar system. This app allows you to speed up or slow down time, travel to any date, and view planetary positions. It also offers widgets for your home screen and Apple Watch complications.

**Highlights:** Simulate planetary orbits, Adjust time speed, Time travel to specific dates, Home screen widgets, Apple Watch integration, View planet overviews

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Io Tip | $1.99 | one-time |
| Europa Tip | $3.99 | one-time |
| Ganymede Tip | $5.99 | one-time |
| Callisto Tip | $9.99 | one-time |


## Frequently asked questions

### Is Monad Calendar Clock free?

Monad Calendar Clock costs $0.99, with no in-app purchases.

### Is Solar System Viewer free?

Solar System Viewer costs $2.99, and also offers in-app purchases.

### Which has better reviews, Monad Calendar Clock or Solar System Viewer?

Solar System Viewer is rated higher. Monad Calendar Clock averages 3.7 out of 5 from 14 ratings, while Solar System Viewer averages 4.4 from 28 ratings.

### Do Monad Calendar Clock or Solar System Viewer have ads?

Neither Monad Calendar Clock nor Solar System Viewer shows ads.

### Which is updated more often, Monad Calendar Clock or Solar System Viewer?

Monad Calendar Clock ships an update every 6 weeks, and Solar System Viewer every 2 months. Most recently, Monad Calendar Clock was updated on October 29, 2026 and Solar System Viewer on October 24, 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.*