# Kadai vs Red Sheet

The clearest difference is in-app purchases: Kadai at none against Red Sheet's 1. Red Sheet's advantage is iOS requirement (18.0 vs 26.2). On price, ads and device support there is nothing between them.

Both are free to download. Red Sheet sells 1 in-app purchase, starting at $2.99 per year. Kadai asks for nothing beyond the download.

## The numbers

| Metric | Kadai | Red Sheet |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | — | Every 4 days |
| Size | 4 MB | 180 MB |
| Requires iOS | 26.2 | **18.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Naruhide Shibazaki](https://appshunter.io/developer/1870444141) | [N-Verse LLC](https://appshunter.io/developer/1868412567) |

## What reviewers say

### Kadai

[App page](https://appshunter.io/ios/app/kadai/id6758034034)

**Features:** macOS Compatibility

**In-app purchases:** none


### Red Sheet

[App page](https://appshunter.io/ios/app/red-sheet-kun-ai-study-sheets/id6775183078)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Red Sheet-kun Premium Annual | $2.99 | per year |


## Frequently asked questions

### Is Kadai free?

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

### Is Red Sheet free?

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

### Do Kadai or Red Sheet have ads?

Both Kadai and Red Sheet show ads.

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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.*