# SOS Explorer vs ASTC

SOS Explorer and ASTC both sit at 4.7 stars, but that hides the real split: 86% of SOS Explorer's written reviews are positive against 0% of ASTC's. SOS Explorer also leads on iOS requirement (12.0 vs 15.5). On price, rating, ratings volume and update cadence there is nothing between them.

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 SOS Explorer against 4.7 for ASTC. Both are backed by a comparable volume of ratings — 20 and 30 respectively. Written reviews are what separate them: 86% of SOS Explorer's written reviews are positive against 0% of ASTC's.

SOS Explorer ships an update every 11 months, ASTC every 12 months. The most recent releases landed on September 7, 2026 and September 11, 2026 respectively.

## The numbers

| Metric | SOS Explorer | ASTC |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (20 ratings)](https://appshunter.io/ios/app/sos-explorer/id1358724422/reviews) | [4.7 (30 ratings)](https://appshunter.io/ios/app/astc/id6466039138/reviews) |
| Number of ratings | 20 | **30** |
| Positive reviews | **85.7% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 11 months** | Every 12 months |
| Monetization | Free | Free |
| Size | 249 MB | 87 MB |
| Requires iOS | **12.0** | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [University of Colorado Boulder](https://appshunter.io/developer/972210292) | [ASSOCIATION OF SCIENCE-TECHNOLOGY CENTERS, INC.](https://appshunter.io/developer/1437372010) |

## What reviewers say

### SOS Explorer

[App page](https://appshunter.io/ios/app/sos-explorer/id1358724422)

Explore interactive animated datasets of Earth and space phenomena, from planetary rings to climate change models. This app brings complex environmental processes to life in an intuitive and captivating way, making learning accessible anywhere.

**Highlights:** Streaming high-resolution datasets, Educational videos, User-guided tours, Analysis tools, 100+ datasets, Global and flat map views

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### ASTC

[App page](https://appshunter.io/ios/app/astc/id6466039138)

Enhance your conference experience by accessing schedules, speaker details, and exhibitor information. Take notes directly on presentation slides in real-time and share insights with attendees via in-app messaging, tweeting, or email.

**Highlights:** View conference schedule, Access speaker and exhibitor details, Take real-time notes on slides, Draw directly on presentation slides, In-app messaging with attendees, Share information via tweet/email

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is SOS Explorer free?

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

### Is ASTC free?

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

### Which has better reviews, SOS Explorer or ASTC?

SOS Explorer and ASTC are both rated 4.7 out of 5 on the App Store, from 20 and 30 ratings respectively.

### Do SOS Explorer or ASTC have ads?

Neither SOS Explorer nor ASTC shows ads.

### Which is updated more often, SOS Explorer or ASTC?

SOS Explorer ships an update every 11 months, and ASTC every 12 months. Most recently, SOS Explorer was updated on September 7, 2026 and ASTC on September 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.*