# Astro Stacker vs RoboTou Stacker

The clearest difference is review sentiment: RoboTou Stacker at 100% against Astro Stacker's 0%. RoboTou Stacker also leads on rating (5.0 vs 1.0) and update cadence (every 5 days vs fortnightly). Astro Stacker's advantage is monetization model (free vs free with in-app purchases) and ratings volume (6 vs 1). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Astro Stacker sells 3 in-app purchases, starting at $12.99 per month and RoboTou Stacker sells 2 in-app purchases, starting at $7.99 per year. Whichever you choose, the download price is not the number that matters.

RoboTou Stacker holds the better App Store score, 5.0 against 1.0. That said, the two scores are not equally well evidenced: Astro Stacker has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 0% of Astro Stacker's written reviews are positive against 100% of RoboTou Stacker's.

Astro Stacker ships an update fortnightly, RoboTou Stacker every 5 days. The most recent releases landed on October 30, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Astro Stacker | RoboTou Stacker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.0 (6 ratings)](https://appshunter.io/ios/app/astro-stacker-star-images/id6753679598/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/robotou-stacker/id6761755082/reviews)** |
| Number of ratings | **6** | 1 |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 5 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 17 MB | 88 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Ahmed Al-Mahmud](https://appshunter.io/developer/1844352476) | [振国 吴](https://appshunter.io/developer/1739933647) |

## What reviewers say

### Astro Stacker

[App page](https://appshunter.io/ios/app/astro-stacker-star-images/id6753679598)

Transform your smartphone into a powerful astrophotography tool. This app uses advanced algorithms to combine multiple night sky photos, reducing noise and revealing hidden celestial details for professional-quality results.

**Highlights:** Advanced stacking algorithms (Average, Median, Maximum, Minimum), Intelligent and manual image alignment, Real-time processing and progress tracking, On-device processing, no cloud upload, Export high-resolution stacked images, Detailed processing insights and logs

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| AstroStacker app | $12.99 | per month |
| AstroStacker app | $99.99 | per year |
| AstroStacker app | $219.00 | one-time |


### RoboTou Stacker

[App page](https://appshunter.io/ios/app/robotou-stacker/id6761755082)

Combine multiple photos directly on your device for enhanced results. This app offers automatic masking and alignment for various photography needs, including starry skies and light trails. Process your images locally without needing an account or cloud sync.

**Highlights:** On-device image stacking, Automatic masking and alignment, Starry sky stacking, Star trail stacking, Car-light trail stacking, Local preview generation, Export to Photos

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RoboTou Stacker Pro Annual | $7.99 | per year |
| RoboTou Stacker Pro Lifetime | $39.99 | one-time |


## Frequently asked questions

### Is Astro Stacker free?

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

### Is RoboTou Stacker free?

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

### Which has better reviews, Astro Stacker or RoboTou Stacker?

RoboTou Stacker is rated higher. Astro Stacker averages 1.0 out of 5 from 6 ratings, while RoboTou Stacker averages 5.0 from 1 ratings.

### Do Astro Stacker or RoboTou Stacker have ads?

Neither Astro Stacker nor RoboTou Stacker shows ads.

### Which is updated more often, Astro Stacker or RoboTou Stacker?

Astro Stacker ships an update fortnightly, and RoboTou Stacker every 5 days. Most recently, Astro Stacker was updated on October 30, 2026 and RoboTou Stacker on October 25, 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.*