# Ultimate Robot Merge vs Sky Stackers

The clearest difference is rating: Sky Stackers at 5.0 against Ultimate Robot Merge's 4.3. Sky Stackers also leads on ads (none vs shown) and update cadence (daily vs every 2 months). Ultimate Robot Merge's advantage is in-app purchases (none vs 1) and ratings volume (95 vs 4). On price, monetization model and device support there is nothing between them.

Both are free to download. Sky Stackers sells 1 one-off in-app purchase. Ultimate Robot Merge asks for nothing beyond the download.

Sky Stackers holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: Ultimate Robot Merge has 95 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 83% of Ultimate Robot Merge's written reviews are positive against 100% of Sky Stackers's.

Ultimate Robot Merge ships an update every 2 months, Sky Stackers daily. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Ultimate Robot Merge | Sky Stackers |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.3 (95 ratings)](https://appshunter.io/ios/app/ultimate-robot-merge/id6449251162/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/sky-stackers/id6764716002/reviews)** |
| Number of ratings | **95** | 4 |
| Positive reviews | 83.3% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Daily** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 236 MB | 8 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 12+ |
| Developer | [Yso Corp](https://appshunter.io/developer/659815325) | [Zackery Allen](https://appshunter.io/developer/1895890813) |

## What reviewers say

### Ultimate Robot Merge

[App page](https://appshunter.io/ios/app/ultimate-robot-merge/id6449251162)

Engage in strategic battles by gathering resources and merging your robots to create powerful upgrades. Overcome adversaries and dominate the arena in this engaging merge game.

**Highlights:** Gather resources, Merge robots, Upgrade robots, Battle adversaries, Strategic gameplay

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

**In-app purchases:** none


### Sky Stackers

[App page](https://appshunter.io/ios/app/sky-stackers/id6764716002)

A fast-paced arcade game where players precisely drop blocks to build a tower as high as possible. The challenge increases with height, offering endless score chasing and quick, satisfying stacking sessions.

**Highlights:** One-touch gameplay, Endless score chasing, Satisfying stacking mechanics, Rewarded continues, Quick play sessions

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Upgrade | $0.99 | one-time |


## Frequently asked questions

### Is Ultimate Robot Merge free?

Ultimate Robot Merge is free to download, with no in-app purchases.

### Is Sky Stackers free?

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

### Which has better reviews, Ultimate Robot Merge or Sky Stackers?

Sky Stackers is rated higher. Ultimate Robot Merge averages 4.3 out of 5 from 95 ratings, while Sky Stackers averages 5.0 from 4 ratings.

### Do Ultimate Robot Merge or Sky Stackers have ads?

Ultimate Robot Merge shows ads; Sky Stackers does not.

### Which is updated more often, Ultimate Robot Merge or Sky Stackers?

Ultimate Robot Merge ships an update every 2 months, and Sky Stackers daily. Most recently, Ultimate Robot Merge was updated on November 3, 2026 and Sky Stackers 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.*