Comet Book vs Starry Map
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Comet Book
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.
- Comet viewing direction and elevation
- Real-time celestial object tracking
- 3D Solar System mode
- Visualize comet and planet motion
- Observing site guidance
Read full descriptionHide full description
The Comet Book app clearly shows when Comets can be viewed and in which direction. The direction and elevation of a Comet can change noticeably in a day due to its fast apparent motion. The moon and a bright planet may be convenient as a guide to find the comet though they have large apparent motion, too. This app determines where Comet is in the sky when it becomes visible at your observing site. You can easily start your observation of a Comet by using Comet Book as a guide to the direction and elevation of the comet. In addition, the new “3D Solar System seen from Space” mode allows you to view the motion of Comets and planets turning around the sun. Please take a look the comet’s movement around our solar system.
Starry Map
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.
- AR celestial identification
- Constellation and star catalog
- Satellite tracking and alerts
- Meteor shower notifications
- Offline functionality
Read full descriptionHide full description
Point your smartphone at the night sky to instantly identify constellations, stars, and satellites. AR overlays show celestial names on the live camera view, and you can swipe to explore any direction. Get alerts for visible ISS passes and meteor showers. Includes: ・88 constellations (with Hevelius illustrations) ・Solar system planets, dwarf planets, asteroids ・Stars up to magnitude 12 ・About 100 Messier objects (nebulae and clusters) ・Over 10,000 satellites ・More than 300 comets ・Meteor showers and asterisms (Summer/Winter Triangle, Big Dipper, etc.) ・Satellite pass alerts (ISS, Hubble) ・Meteor shower peak notifications Works offline (satellite data won't update). Terms of Service https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | Comet Book | Starry Map |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | 4.5 (246 ratings) |
| Positive reviews | 54.9% of reviews | 62.4% of reviews — better |
| Number of ratings | 2 | 246 — better |
| Update frequency | Every 6 months | Every 2 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 10 MB | 103 MB |
| Age rating | 9+ | 4+ |
| Developer | Vixen Co.,Ltd. | にゃんこソフトウェア |
Customer experience
Comet Book
Starry Map
In-app purchases
Comet Book
No in-app purchases
Starry Map
- Unlock Features2 variants$0.991 Month
- Unlock Features7 Days trial2 variants$0.991 Month
- Unlock Features$3.991 Year
Show 1 moreShow fewer
- Unlock Features7 Days trial$3.991 Year
- Unlock Features (Lifetime)$9.99
