# AstroStacker vs RoboTou Stacker

The clearest difference is review sentiment: RoboTou Stacker at 100% against AstroStacker's 0%. RoboTou Stacker also leads on rating (5.0 vs 1.1) and update cadence (every 5 days vs every 2 weeks). AstroStacker's advantage is ratings volume (7 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. AstroStacker 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 1.1. That said, the two scores are not equally well evidenced: AstroStacker has 7 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 0% of AstroStacker's written reviews are positive against 100% of RoboTou Stacker's.

AstroStacker ships an update every 2 weeks, RoboTou Stacker every 5 days. The most recent releases landed on November 12, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | AstroStacker | RoboTou Stacker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.1 (7 ratings)](https://appshunter.io/ios/app/astrostacker-stack-the-sky/id6753679598/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/robotou-stacker/id6761755082/reviews)** |
| Number of ratings | **7** | 1 |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 5 days** |
| Monetization | Freemium | 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

### AstroStacker

[App page](https://appshunter.io/ios/app/astrostacker-stack-the-sky/id6753679598)

Enhance your night sky photos by stacking multiple exposures into a single, detailed image. This app automatically aligns stars, reduces noise, and offers tools to refine your astrophotography results directly on your iPhone or iPad.

**Highlights:** Stack multiple night sky photos, Automatic star alignment, Noise reduction for clearer images, Advanced editing tools, Support for calibration frames (Pro), On-device processing

**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 AstroStacker free?

AstroStacker 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, AstroStacker or RoboTou Stacker?

RoboTou Stacker is rated higher. AstroStacker averages 1.1 out of 5 from 7 ratings, while RoboTou Stacker averages 5.0 from 1 ratings.

### Do AstroStacker or RoboTou Stacker have ads?

Neither AstroStacker nor RoboTou Stacker shows ads.

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

AstroStacker ships an update every 2 weeks, and RoboTou Stacker every 5 days. Most recently, AstroStacker was updated on November 12, 2026 and RoboTou Stacker on October 31, 2026.

---

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