# Fallacy vs Japanese21

The clearest difference is update cadence: Japanese21 at every 4 days against Fallacy's fortnightly. Fallacy's advantage is iOS requirement (15.1 vs 17.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Fallacy sells 6 in-app purchases, starting at $6.99 per 7 days and Japanese21 sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Fallacy ships an update fortnightly, Japanese21 every 4 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Fallacy | Japanese21 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (58 ratings)](https://appshunter.io/ios/app/fallacy-brain-training-logic/id6743923575/reviews)** | — |
| Number of ratings | **58** | — |
| Positive reviews | 77.8% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 134 MB | 383 MB |
| Requires iOS | **15.1** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [VERTEX STUDIOS LTD](https://appshunter.io/developer/1805080787) | [OLE PETTER HAUGEN](https://appshunter.io/developer/1831337755) |

## What reviewers say

### Fallacy

[App page](https://appshunter.io/ios/app/fallacy-brain-training-logic/id6743923575)

This app teaches logical reasoning and critical thinking skills by turning the identification of logical fallacies and cognitive biases into a game. It offers structured brain training with daily exercises and timed challenges, using real-world scenarios and media to build applied intelligence.

**Highlights:** Identify 30+ logical fallacies, Recognize 20+ cognitive biases, Daily brain exercises, Timed reasoning challenges, Debate Mode with real-world arguments, Progressive difficulty levels

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Premium Access | $6.99 | per 7 days |
| Monthly Subscription Fallacy | $12.99 | per month |
| Monthly Premium Access | $12.99 | per month |
| Yearly Premium Access | $49.99 | per year |
| Yearly Subscription Fallacy | $59.99 | per year |
| Lifetime Access - Premium | $79.99 | one-time |


### Japanese21

[App page](https://appshunter.io/ios/app/japanese21/id6760900290)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Japanese21 Pro | $19.99 | one-time |


## Frequently asked questions

### Is Fallacy free?

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

### Is Japanese21 free?

Japanese21 is free to download, with in-app purchases available.

### Do Fallacy or Japanese21 have ads?

Neither Fallacy nor Japanese21 shows ads.

### Which is updated more often, Fallacy or Japanese21?

Fallacy ships an update fortnightly, and Japanese21 every 4 days. Most recently, Fallacy was updated on October 24, 2026 and Japanese21 on October 25, 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.*