# Comet Book vs Starry Map

The clearest difference is rating: Comet Book at 5.0 against Starry Map's 4.5. Comet Book also leads on in-app purchases (none vs 7) and ads (none vs shown). Starry Map's advantage is update cadence (every 2 weeks vs every 6 months) and ratings volume (246 vs 2). On price, review sentiment and device support there is nothing between them.

Both are free to download. Starry Map sells 5 in-app purchases, starting at $0.99 per month. Comet Book asks for nothing beyond the download.

Comet Book holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Starry Map has 246 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 55% of Comet Book's written reviews are positive against 62% of Starry Map's, so the app with the better star average is not the one people write more warmly about.

Comet Book ships an update every 6 months, Starry Map every 2 weeks. The most recent releases landed on September 21, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | Comet Book | Starry Map |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/comet-book/id604782335/reviews)** | [4.5 (246 ratings)](https://appshunter.io/ios/app/starry-map/id1176591850/reviews) |
| Number of ratings | 2 | **246** |
| Positive reviews | 54.9% of reviews | **62.4% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 6 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 10 MB | 103 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 9+ | 4+ |
| Developer | [Vixen Co.,Ltd.](https://appshunter.io/developer/536188843) | [にゃんこソフトウェア](https://appshunter.io/developer/1843663669) |

## What reviewers say

### Comet Book

[App page](https://appshunter.io/ios/app/comet-book/id604782335)

Discover and track comets with this educational app. It provides real-time direction and elevation data to help you locate celestial objects in the night sky. Explore the solar system in 3D and visualize the movement of comets and planets.

**Highlights:** Comet viewing direction and elevation, Real-time celestial object tracking, 3D Solar System mode, Visualize comet and planet motion, Observing site guidance

**In-app purchases:** none


### Starry Map

[App page](https://appshunter.io/ios/app/starry-map/id1176591850)

Identify stars, constellations, and satellites by pointing your phone at the night sky. Augmented reality overlays display celestial names in real-time. Receive notifications for upcoming satellite passes and meteor showers.

**Highlights:** AR celestial identification, Constellation and star catalog, Satellite tracking and alerts, Meteor shower notifications, Offline functionality

**Features:** macOS Compatibility

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Features | $0.99 | per month |
| Unlock Features | $0.99 | per month |
| Unlock Features | $3.99 | per year |
| Unlock Features | $3.99 | per year |
| Unlock Features (Lifetime) | $9.99 | one-time |


## Frequently asked questions

### Is Comet Book free?

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

### Is Starry Map free?

Starry Map is free to download, with in-app purchases available.

### Which has better reviews, Comet Book or Starry Map?

Comet Book is rated higher. Comet Book averages 5.0 out of 5 from 2 ratings, while Starry Map averages 4.5 from 246 ratings.

### Do Comet Book or Starry Map have ads?

Starry Map shows ads; Comet Book does not.

### Which is updated more often, Comet Book or Starry Map?

Comet Book ships an update every 6 months, and Starry Map every 2 weeks. Most recently, Comet Book was updated on September 21, 2026 and Starry Map on September 19, 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.*