# Grav Box vs Kurotto Extreme

The clearest difference is in-app purchases: Kurotto Extreme at none against Grav Box's 10. Kurotto Extreme also leads on rating (5.0 vs 4.8). Grav Box's advantage is update cadence (every 5 months vs every 22 months) and ratings volume (26 vs 1). On price, review sentiment, ads and device support there is nothing between them.

Both are free to download. Grav Box sells 10 one-off in-app purchases. Kurotto Extreme asks for nothing beyond the download.

Kurotto Extreme holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Grav Box has 26 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 96% of Grav Box's written reviews are positive against 100% of Kurotto Extreme's.

Grav Box ships an update every 5 months, Kurotto Extreme every 22 months. Both last shipped on October 5, 2026.

## The numbers

| Metric | Grav Box | Kurotto Extreme |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (26 ratings)](https://appshunter.io/ios/app/grav-box/id1050320618/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/kurotto-extreme/id1499171663/reviews)** |
| Number of ratings | **26** | 1 |
| Positive reviews | 96.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | **Every 5 months** | Every 22 months |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 10 MB | 22 MB |
| Requires iOS | 14.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Gianluca Capraro](https://appshunter.io/developer/1691787728) | [Christophe Baranger](https://appshunter.io/developer/982794089) |

## What reviewers say

### Grav Box

[App page](https://appshunter.io/ios/app/grav-box/id1050320618)

Control gravity with a tap and hold to manipulate objects. Customize their appearance, explore dynamic physics, and engage in arcade challenges with leaderboards and achievements.

**Highlights:** Tap and hold to control gravity, Customize grav colors and emojis, Dynamic backgrounds and physics effects, Arcade mode with achievements, Global leaderboards, In-game events like black holes

**Features:** macOS Compatibility

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Gold Blocks (100) Pack | $0.99 | one-time |
| Light Portal | $0.99 | one-time |
| Dark Portal | $0.99 | one-time |
| Grav Box | $0.99 | one-time |
| Midnight | $0.99 | one-time |
| Daybreak | $0.99 | one-time |
| Beach | $0.99 | one-time |
| Jungle | $0.99 | one-time |
| Mist | $0.99 | one-time |
| Gold Blocks (1000) Pack | $4.99 | one-time |


### Kurotto Extreme

[App page](https://appshunter.io/ios/app/kurotto-extreme/id1499171663)

A logic puzzle game originating from Japan with simple rules for hours of engaging challenges. Fill empty cells based on numbered circles indicating continuous black cells, with no time limits and autosave functionality.

**Highlights:** 350+ challenges across 7 difficulty levels, 7 new daily challenges, Autosave progress, No time limits, 2 global leaderboards, Full tutorial

**In-app purchases:** none


## Frequently asked questions

### Is Grav Box free?

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

### Is Kurotto Extreme free?

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

### Which has better reviews, Grav Box or Kurotto Extreme?

Kurotto Extreme is rated higher. Grav Box averages 4.8 out of 5 from 26 ratings, while Kurotto Extreme averages 5.0 from 1 ratings.

### Do Grav Box or Kurotto Extreme have ads?

Both Grav Box and Kurotto Extreme show ads.

### Which is updated more often, Grav Box or Kurotto Extreme?

Grav Box ships an update every 5 months, and Kurotto Extreme every 22 months. Most recently, Grav Box was updated on October 5, 2026 and Kurotto Extreme on October 5, 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.*