Cosmology vs ASGuide
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Cosmology
Explore the universe with stunning high-resolution images of celestial bodies. Journey through space, visiting planets and their moons, while learning about the evolution of space, time, and matter. Ponder the profound mysteries of existence.
- High-resolution images of planets, nebulae, and galaxies
- Interactive space travel to planets and moons
- Learn about the evolution of space, time, and matter
- Expert narration by Dr. Aaron Day
- Exploration of existential mysteries of the universe
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Explore the universe with 100s of high resolution images of planets, nebulae, galaxies, and more. Travel through space, visiting every planet and their major moons. Learn about the creation of space, time, and matter, and their evolution into stars, galaxies, and planets in the present day. Ponder the deep, existential mysteries of the universe. The story of creation is told by Dr. Aaron Day. Dr. Day earned his Ph.D. at the University of California, San Diego for research in cosmology.
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 ratings volume: Cosmology at 505 against ASGuide's 9. Cosmology also leads on update cadence (monthly vs every 4 months) and device support (3 vs 1). ASGuide's advantage is review sentiment (100% vs 89%). On price, rating, 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.
On the App Store both sit at effectively the same score — 4.7 for Cosmology against 4.8 for ASGuide. That said, the two scores are not equally well evidenced: Cosmology has 505 ratings behind it against 9, so its average is the more settled of the two. Written reviews are what separate them: 89% of Cosmology's written reviews are positive against 100% of ASGuide's.
Cosmology ships an update monthly, ASGuide every 4 months. The most recent releases landed on September 28, 2026 and September 14, 2026 respectively.
| Parameter | Cosmology | ASGuide |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (505 ratings) | 4.8 (9 ratings) — better |
| Positive reviews | 88.6% of reviews | 100.0% of reviews — better |
| Number of ratings | 505 — better | 9 |
| Update frequency | Monthly — better | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 11.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 190 MB | 33 MB |
| Age rating | 4+ | 4+ |
| Developer | Aaron Day | Philip Perez |
Customer experience
Cosmology
ASGuide
Bugs and requests
Cosmology
Reported bugs
2 issues- Image display interference/hacking concerns
- App feels incomplete in certain sections
Requested features
6 requests- More interactive activities and engagement features
- Text-to-speech functionality
- More detailed explanations for beginner-level users
- Additional sub-categories and content sections
- Regular updates with current astronomical images
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- Alternative cosmological perspectives or viewpoints
ASGuide
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Cosmology
No in-app purchases
ASGuide
No in-app purchases
