SDO Viewer vs KeckWatch
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SDO Viewer
Access and view the latest images from the Solar Dynamics Observatory. Receive push notifications when new images become available, keeping you updated on solar activity.
- Download SDO images
- Display latest solar images
- Push notifications for new images
- Courtesy of NASA/SDO science teams
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SDO Viewer is a simple application for downloading and displaying the latest images taken by the Solar Dynamics Observatory (SDO). It includes push notifications so you can be notified by a badge on the application when new images are available. SDO Viewer, by the creator of SoHO Viewer. Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
KeckWatch
Explore the cosmos with detailed information on stars, planets, galaxies, and nebulae. Discover celestial objects using your device's compass and GPS, and stay updated with news from the W. M. Keck Observatory. Features a night-vision-friendly red interface and offline access.
- Offline celestial exploration
- Real-time telescope status
- Compass and GPS integration
- Detailed object information
- Hawaiian star names
- Night vision red interface
- Keck Observatory news
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KeckWatch is brought to you by W. M. Keck Observatory, which operates the two largest optical/infrared telescopes on Earth from nearly 14,000 feet on Maunakea in Hawaii. Since first science in 1993 they have become the two most scientifically productive telescopes on Earth. With KeckWatch, you can share in their discoveries. Sporting thousands of stars, all 8 (sorry, Pluto) planets, galaxies, nebula and star clusters, along with status updates and news from Keck Observatory you’ll learn where Orion might be, or what planet was shimmering above the house last night. Features include: •No Internet required. Just a sense of wonder. •Up to date Keck news •See the current status of each telescope, what instruments are in use and what organization is booked for that evening’s observing •See where each scope is currently aimed. •Stars are shown with both standard and traditional Hawaiian names •Zoom in on the planets, see Jupiter and her moons or the rings of Saturn. •See where other users with Beacons. •Compass aware, just aim and gaze. •Thousands of pinpoint stars scintillating like diamond dust in the palm of your hand •Realistic ghostly band of the Milky Way •Stories behind each constellation •Viewpoint Lock keeps any planet centered •Galaxies, nebula and star clusters •Hubble Space Telescope images •All 8 planets (Pluto is optional) •GPS aware •Red interface to preserve your night vision •What's Up? Gives a quick one snapshot overview of where all of the important stuff is •Touching the sky to reveal hidden data for each object •Planetary data and information
Screenshots
Verdict
The clearest difference is rating: KeckWatch at 4.3 against SDO Viewer's 3.0. KeckWatch also leads on review sentiment (83% vs 60%) and update cadence (every 5 weeks vs every 2 months). On price, ratings volume, 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.
KeckWatch holds the better App Store score, 4.3 against 3.0. Both are backed by a comparable volume of ratings — 5 and 9 respectively. Written reviews point the same way: 60% of SDO Viewer's written reviews are positive against 83% of KeckWatch's.
SDO Viewer ships an update every 2 months, KeckWatch every 5 weeks. The most recent releases landed on October 7, 2026 and October 14, 2026 respectively.
| Parameter | SDO Viewer | KeckWatch |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (5 ratings) | 4.3 (9 ratings) — better |
| Positive reviews | 60.0% of reviews | 83.3% of reviews — better |
| Number of ratings | 5 | 9 — better |
| Update frequency | Every 2 months | Every 5 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.0 | 7.1 — better |
| Further details — not scored | ||
| Size | 6 MB | 147 MB |
| Age rating | 4+ | 4+ |
| Developer | Jérôme Diaz | Mike Smithwick |
Customer experience
SDO Viewer
KeckWatch
In-app purchases
SDO Viewer
No in-app purchases
KeckWatch
No in-app purchases









