Comet Book vs ASGuide
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
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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.
ASGuide
Explore the night sky with this astronomy companion. Discover planets, galaxies, nebulae, and more visible from your location. Generate custom viewing lists and preview celestial objects with an interactive sky atlas.
- Discover celestial objects visible from your location
- Generate custom viewing lists
- View detailed observation information
- Interactive sky atlas preview
- Dark mode for nighttime viewing
- Sunrise/sunset and moon phase dashboard
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Discover the wonders visible in your sky tonight. ASGuide (Astronomy Sky Guide) turns your location and observing time into a personal guide to the night sky. Discover visible planets, galaxies, nebulae, stars, star clusters, and galactic regions. Plan an observation, explore from home, or find your next celestial target. Find objects worth viewing and learn more about every discovery: - See what is visible from your location and when to observe it. View rise, transit, and set times. - Filter by magnitude, altitude above the horizon, constellation, object type, and more. - Search by common name, catalog number, constellation, object type, or detailed classification. - Browse the solar system and deep-sky categories. - Return quickly to recent searches and recently viewed objects. - See which planets are visible. - Save favorite objects for future viewing. - Use your current location or select any location on Earth. - Check sunrise, sunset, twilight, and night times. - Follow the current moon phase, illumination, moonrise, moonset, and the next new and full moons. - Open high-resolution imagery and explore objects with the interactive sky atlas. Customize the Home screen with the information that matters to you. Use the dark appearance for nighttime observations, or the standard iOS appearance. Your next night-sky discovery starts with ASGuide.
Screenshots
Verdict
The clearest difference is review sentiment: ASGuide at 100% against Comet Book's 55%. ASGuide also leads on ratings volume (9 vs 2). Comet Book's advantage is rating (5.0 vs 4.8) and device support (3 vs 1). On price, update cadence, ads and in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.
Comet Book holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 2 and 9 respectively. Written reviews complicate that: 55% of Comet Book's written reviews are positive against 100% of ASGuide'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, ASGuide every 4 months. The most recent releases landed on September 21, 2026 and September 1, 2026 respectively.
| Parameter | Comet Book | ASGuide |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | 4.8 (9 ratings) |
| Positive reviews | 54.9% of reviews | 100.0% of reviews — better |
| Number of ratings | 2 | 9 — better |
| Update frequency | Every 6 months | Every 4 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 12.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 10 MB | 33 MB |
| Age rating | 9+ | 4+ |
| Developer | Vixen Co.,Ltd. | Philip Perez |
Customer experience
Comet Book
ASGuide
In-app purchases
Comet Book
No in-app purchases
ASGuide
No in-app purchases









