# APOD Explorer vs Sideris

The clearest difference is update cadence: Sideris at every 2 weeks against APOD Explorer's every 6 weeks. Sideris also leads on iOS requirement (15.0 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. APOD Explorer sells 3 one-off in-app purchases and Sideris sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

APOD Explorer ships an update every 6 weeks, Sideris every 2 weeks. Both last shipped on October 31, 2026.

## The numbers

| Metric | APOD Explorer | Sideris |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 2 weeks** |
| Size | 39 MB | 137 MB |
| Requires iOS | 26.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Diego Carrera Alonso](https://appshunter.io/developer/6787161862) | [Loris BERT](https://appshunter.io/developer/6809145520) |

## What reviewers say

### APOD Explorer

[App page](https://appshunter.io/ios/app/apod-explorer-astronomy/id6787161860)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lunar tip | $1.99 | one-time |
| Planetary tip | $3.99 | one-time |
| Stellar tip | $8.99 | one-time |


### Sideris

[App page](https://appshunter.io/ios/app/sideris-sky-map-plate-solver/id6809145518)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlimited Plate Solving | $9.99 | one-time |


## Frequently asked questions

### Is APOD Explorer free?

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

### Is Sideris free?

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

### Do APOD Explorer or Sideris have ads?

Neither APOD Explorer nor Sideris shows ads.

### Which is updated more often, APOD Explorer or Sideris?

APOD Explorer ships an update every 6 weeks, and Sideris every 2 weeks. Most recently, APOD Explorer was updated on October 31, 2026 and Sideris on October 31, 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.*