The Sky by Redshift vs Astronomy Observer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
The Sky by Redshift
This app is a powerful yet easy-to-use planetarium that acts as your daily astronomy companion. Simply point your device at the sky to identify planets, stars, and constellations, and explore celestial objects with detailed views and informative explanations.
- Identify stars, planets, and constellations
- Track celestial object paths
- Simulate astronomical events
- Explore deep-space objects
- Learn about astronomical phenomena
- Eclipse timetable and simulation
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Developed in collaboration with THAMES & KOSMOS: The Sky – Astronomy, a powerful and easy-to-use planetarium – your daily companion for observing the sky! Which star is this? Where do I find Mars? Is it the ISS up there? Hold your smartphone or tablet up to the sky and see which planets, stars, or constellations are above you. Where is Jupiter and how can I find my zodiac in the sky? The Sky shows you the position of celestial objects in the sky with just a few taps. Get close-up views not only of near-Earth planets and moons, but also experience deep-space objects in stunning detail. What do the Saturnian moons look like? The Sky takes you on a breath-taking journey into the infinite realms of outer space. Fly to planets, stars, and other celestial bodies and let the app tell you about our Universe. What is a solar eclipse and what does an opposition of Mars mean? The Sky answers your questions with stunning animations and insightful explanations. Thus, even beginners will be able to understand the mechanics and to visually imagine the most important celestial events. No matter if you are a beginner or amateur astronomer, child or adult - with the intuitive app The Sky, everyone will immediately understand the sky - without much prior knowledge and long training. Shine with your knowledge of the sky, around the campfire or on night walks: with The Sky, astronomy will always be a pleasure! Discover the joy of watching the skies and the age-old fascination with space that has inspired mankind for millennia – and become part of the worldwide Redshift community. The app contains more than 9,000 stars, 88 constellations, hundreds of moons, asteroids and comets, as well as 200 spectacular deep-sky objects - all with accurate position calculation and motion tracking in real time. At a glance: • Recognize the stars and constellations of the night sky • Identify planets, moons, comets, and satellites and track their paths • Take breath-taking flights through space to distant stars and colorful nebulae • See what’s going on in the sky tonight with a direct simulation of the events • Learn to understand astronomical phenomena and events New in version 2.0: • Eclipse Timetable • Orbits of celestial objects • Expanded database with 6500 cities worldwide, including 2500 cities in the United States Were you able to witness the total solar eclipse in North America on April 8, 2024? This app contains everything you need know about this magical event: • Detailed description of the path of the eclipse in Mexico, the USA and Canada • Information on how to safely observe a solar eclipse • Eclipse timetable with the exact times for your location or best viewing position • Direct simulation of the eclipse in exciting animations • Sky map with the planets and stars that could be seen during the totality phase • Illustrated explanations of how a solar eclipse occurs • Everything about solar eclipses: Explanations and facts, illustrated with pictures and videos • Location selection via map, location search or GPS or selection of the "best position" for observation Your thirst for knowledge is not yet satisfied? With the premium subscription, you can activate many additional spaceflights and orbits as well as additional knowledge sections of "Discover astronomy". Here you can find more spectacular images and videos of the total solar eclipse on April 8, 2024. There is also an eclipse calendar with all solar and lunar eclipses between 1900 and 2100 and a guided tour of the U.S. MARS 2020 mission. This tour includes images and animations of the landing on Mars, as well as of the environment at the landing site of the Mars rover Perseverance. ***** Questions or suggestions for improvements: Mail to support@redshiftsky.com We are looking forward to your feedback! For more information on news and updates: redshiftsky.com www.redshiftsky.com/terms-of-use-the-sky/ *****
Astronomy Observer
This app helps astronomical observers plan their viewing sessions by calculating and displaying the positions of celestial bodies. It offers AR views, a catalog of stars and deep sky objects, and an astronomical event calendar. Premium features include ad-free viewing and access to a year of ephemeris data.
- AR celestial body positioning
- Daily sun-moon position and planet rise/set
- Catalog of stars, planets, and deep sky objects
- Astronomical event calendar
- Yearly ephemeris calculation
- Constellation and star identification
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Astronomy Observer app is an app that help astronomical observers to arrange their observation plans reasonably. Thanks to the improvement of the computing power of mobile phones and the application of new technologies (AR), it is possible to calculate the position of celestial bodies and the celestial ephemeris on the mobile phone, and AR can display the positions of celestial bodies. The Astronomy Observer not only calculates the daily sun-moon position, planets rise and set, constellations, important stars, and messier objects which can be seen . In addition, various types of celestial bodies and important star catalogs are also collected, and the position, rise and set of each celestial body are calculated, and finally the ephemeris of the celestial body is calculated for one year. AR shows the constellation division, constellation position, star position, important star display, solar system celestial position. The App is divided into the following parts 1. Daily: Daily twilight, moonrise and moonset, planets, and constellations, stars, messier 2. Browse: Browse constellations, stars, solar systems (sun, moon, planet, comet), deep sky objects (messier, galaxy, star clusters, nebulae), important star catalogs (HR, HD, HIP, SAO, CCDM, GCVS, TYChO, NGC) 3. Event: Calendar of astronomical phenomen 4. AR: AR shows the position of celestial bodies 5. Mine: 【Astronomy Observer Membership】 View all the celestial bodies catalog, One year ephemeris for all celestial bodies can be viewed, View AR images of any time,no ads Purchase rules: [Monthly Membership] Purchase a monthly member for $ 0.99 / month and renew it automatically every month. [Annual Membership] 4.99 $ / year to purchase annual annual membership and automatically renew it annually. [Lifetime Membership] $ 14.99, only need to purchase once, valid for life [Prices in different countries or regions should be converted according to the US dollar exchange rate] Purchase Notes: 1. The account will be automatically renewed and deducted the corresponding fee 1 day before the expiration. 2. If you need to cancel the renewal, please cancel in your personal iTunes account at least 1 day in advance. 3. After purchase, users can manage or turn off automatic renewal in personal account settings. Terms of Services : http://www.astronomyobserver.net/h5/astronomy/user/en Privacy policy: http://www.astronomyobserver.net/h5/astronomy/privacy/en
Screenshots
Verdict
The clearest difference is ads: The Sky by Redshift at none against Astronomy Observer's shown. The Sky by Redshift also leads on ratings volume (816 vs 28). Astronomy Observer's advantage is iOS requirement (11.0 vs 15.6). On price, rating, review sentiment and update cadence 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. The Sky by Redshift sells 2 in-app purchases, starting at $0.99 per month and Astronomy Observer sells 3 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.7 for The Sky by Redshift against 4.6 for Astronomy Observer. That said, the two scores are not equally well evidenced: The Sky by Redshift has 816 ratings behind it against 28, so its average is the more settled of the two. Written reviews are what separate them: 65% of The Sky by Redshift's written reviews are positive against 58% of Astronomy Observer's.
The Sky by Redshift ships an update every 2 months, Astronomy Observer monthly. The most recent releases landed on October 15, 2026 and October 18, 2026 respectively.
| Parameter | The Sky by Redshift | Astronomy Observer |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (816 ratings) — better | 4.6 (28 ratings) |
| Positive reviews | 65.0% of reviews — better | 58.3% of reviews |
| Number of ratings | 816 — better | 28 |
| Update frequency | Every 2 months | Monthly — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 11.0 — better |
| Further details — not scored | ||
| Size | 472 MB | 51 MB |
| Age rating | 4+ | 4+ |
| Developer | USM | 雪平 王 |
Customer experience
The Sky by Redshift
Astronomy Observer
Bugs and requests
The Sky by Redshift
Reported bugs
1 issue- Unauthorized access to private systems
Requested features
3 requests- Red light option to preserve night vision
- Smaller, less obtrusive pointer
- More features and accurate information
Astronomy Observer
Not enough reviews yet to summarise bugs or requests.
In-app purchases
The Sky by Redshift
- The Sky Premium 1 Month$0.991 Month
- The Sky Premium 1 Year$3.991 Year
Astronomy Observer
- Monthly membership$0.991 Month
- Annually Membership$5.991 Year
- lifetime membership$14.99






