# Kidoi vs Ruidaichan

The clearest difference is update cadence: Ruidaichan at every 5 days against Kidoi's fortnightly. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Kidoi sells 2 in-app purchases, starting at $0.99 per month and Ruidaichan sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

Kidoi ships an update fortnightly, Ruidaichan every 5 days. The most recent releases landed on October 24, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Kidoi | Ruidaichan |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/kidoi-ai-object-identifier/id6747200408/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 5 days** |
| Size | 155 MB | 18 MB |
| Requires iOS | 17.6 | **16.6** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [MUSTAFA BATIN EFE](https://appshunter.io/developer/1820231555) | [Naoki Ohashi](https://appshunter.io/developer/1880818831) |

## What reviewers say

### Kidoi

[App page](https://appshunter.io/ios/app/kidoi-ai-object-identifier/id6747200408)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly | $0.99 | per month |
| Premium Yearly | $9.99 | per year |


### Ruidaichan

[App page](https://appshunter.io/ios/app/ruidaichan-extra-math-practice/id6759811359)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Light Plan | $1.99 | per month |
| Premium Plan | $4.99 | per month |


## Frequently asked questions

### Is Kidoi free?

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

### Is Ruidaichan free?

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

### Do Kidoi or Ruidaichan have ads?

Neither Kidoi nor Ruidaichan shows ads.

### Which is updated more often, Kidoi or Ruidaichan?

Kidoi ships an update fortnightly, and Ruidaichan every 5 days. Most recently, Kidoi was updated on October 24, 2026 and Ruidaichan on October 19, 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.*