# ERAI! vs Stacky

The clearest difference is in-app purchases: ERAI! at none against Stacky's 1. ERAI! also leads on update cadence (weekly vs every 3 weeks) and iOS requirement (15.0 vs 17.6). On price, ads and device support there is nothing between them.

Both are free to download. Stacky sells 1 one-off in-app purchase. ERAI! asks for nothing beyond the download.

ERAI! ships an update weekly, Stacky every 3 weeks. The most recent releases landed on October 16, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | ERAI! | Stacky |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | **Weekly** | Every 3 weeks |
| Size | 18 MB | 15 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Kosuke Shimada](https://appshunter.io/developer/1529796493) | [Signet LLC](https://appshunter.io/developer/1880910401) |

## What reviewers say

### ERAI!

[App page](https://appshunter.io/ios/app/erai/id1529796491)

**Features:** macOS Compatibility

**In-app purchases:** none


### Stacky

[App page](https://appshunter.io/ios/app/stacky/id6759818275)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Stacky プレミアム | $0.49 | one-time |


## Frequently asked questions

### Is ERAI! free?

ERAI! is free to download, with no in-app purchases.

### Is Stacky free?

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

### Do ERAI! or Stacky have ads?

Both ERAI! and Stacky show ads.

### Which is updated more often, ERAI! or Stacky?

ERAI! ships an update weekly, and Stacky every 3 weeks. Most recently, ERAI! was updated on October 16, 2026 and Stacky on October 6, 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.*