# SDO Viewer vs Exoplanet Explorer

The clearest difference is rating: Exoplanet Explorer at 4.6 against SDO Viewer's 3.0. Exoplanet Explorer also leads on review sentiment (100% vs 60%) and update cadence (every 2 weeks vs every 2 months). SDO Viewer's advantage is in-app purchases (none vs 4) and iOS requirement (13.0 vs 17.6). On price and ads there is nothing between them.

Both are free to download. Exoplanet Explorer sells 4 in-app purchases, starting at $2.99 per 3 months. SDO Viewer asks for nothing beyond the download.

Exoplanet Explorer holds the better App Store score, 4.6 against 3.0. That said, the two scores are not equally well evidenced: Exoplanet Explorer has 70 ratings behind it against 5, so its average is the more settled of the two. Written reviews point the same way: 60% of SDO Viewer's written reviews are positive against 100% of Exoplanet Explorer's.

SDO Viewer ships an update every 2 months, Exoplanet Explorer every 2 weeks. The most recent releases landed on October 7, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | SDO Viewer | Exoplanet Explorer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (5 ratings)](https://appshunter.io/ios/app/sdo-viewer/id913723111/reviews) | **[4.6 (70 ratings)](https://appshunter.io/ios/app/exoplanet-explorer/id1457614833/reviews)** |
| Number of ratings | 5 | **70** |
| Positive reviews | 60.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | **Free** | Freemium |
| Size | 6 MB | 169 MB |
| Requires iOS | **13.0** | 17.6 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, Mac, Apple Watch, Vision Pro** |
| Age rating | 4+ | 4+ |
| Developer | [Jérôme Diaz](https://appshunter.io/developer/334987620) | [Carsten Knoblich](https://appshunter.io/developer/541438854) |

## What reviewers say

### SDO Viewer

[App page](https://appshunter.io/ios/app/sdo-viewer/id913723111)

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.

**Highlights:** Download SDO images, Display latest solar images, Push notifications for new images, Courtesy of NASA/SDO science teams

**Features:** macOS Compatibility

**In-app purchases:** none


### Exoplanet Explorer

[App page](https://appshunter.io/ios/app/exoplanet-explorer/id1457614833)

Explore a vast catalog of over 6,000 confirmed exoplanets with detailed scientific data. Compare worlds, visualize habitable zones, and track new discoveries. Ideal for stargazers, students, educators, and researchers.

**Highlights:** 6,000+ confirmed exoplanets, Detailed scientific data, Advanced filtering and sorting, Planet comparison tool, Habitable zone analysis, Home screen widgets, Apple Watch companion app

**Features:** Family Sharing, Apple Watch app

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 3 months subscription | $2.99 | per 3 months |
| 12 months subscription | $6.99 | per year |
| Big supporting tip | $2.99 | one-time |
| Really big supporting tip | $4.99 | one-time |


## Frequently asked questions

### Is SDO Viewer free?

SDO Viewer is free to download, with no in-app purchases.

### Is Exoplanet Explorer free?

Exoplanet Explorer is free to download, with in-app purchases available.

### Which has better reviews, SDO Viewer or Exoplanet Explorer?

Exoplanet Explorer is rated higher. SDO Viewer averages 3.0 out of 5 from 5 ratings, while Exoplanet Explorer averages 4.6 from 70 ratings.

### Do SDO Viewer or Exoplanet Explorer have ads?

Neither SDO Viewer nor Exoplanet Explorer shows ads.

### Which is updated more often, SDO Viewer or Exoplanet Explorer?

SDO Viewer ships an update every 2 months, and Exoplanet Explorer every 2 weeks. Most recently, SDO Viewer was updated on October 7, 2026 and Exoplanet Explorer on October 11, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*