# SDO Viewer vs Astris

The clearest difference is iOS requirement: SDO Viewer at 13.0 against Astris's 15.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

SDO Viewer ships an update every 2 months, Astris every 3 months. The most recent releases landed on October 7, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | SDO Viewer | Astris |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (5 ratings)](https://appshunter.io/ios/app/sdo-viewer/id913723111/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 3 months |
| Monetization | Free | — |
| Size | 6 MB | 21 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jérôme Diaz](https://appshunter.io/developer/334987620) | [ISTITUTI EDMONDO DE AMICIS SRL](https://appshunter.io/developer/1219261025) |

## 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


### Astris

[App page](https://appshunter.io/ios/app/astris/id6454899891)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SDO Viewer free?

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

### Is Astris free?

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

### Do SDO Viewer or Astris have ads?

Neither SDO Viewer nor Astris shows ads.

### Which is updated more often, SDO Viewer or Astris?

SDO Viewer ships an update every 2 months, and Astris every 3 months. Most recently, SDO Viewer was updated on October 7, 2026 and Astris on October 6, 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.*