# π Challenge vs NBack³

The clearest difference is in-app purchases: π Challenge at none against NBack³'s 1. π Challenge also leads on ads (none vs shown) and iOS requirement (13.0 vs 17.0). NBack³'s advantage is update cadence (every 4 days vs every 9 months). On price and device support there is nothing between them.

Both are free to download. NBack³ sells 1 in-app purchase, starting at $0.49 per month. π Challenge asks for nothing beyond the download.

π Challenge ships an update every 9 months, NBack³ every 4 days. The most recent releases landed on September 24, 2026 and August 14, 2026 respectively.

## The numbers

| Metric | π Challenge | NBack³ |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 71.4% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 9 months | **Every 4 days** |
| Monetization | — | Free with in-app purchases |
| Size | 29 MB | 20 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Warashibe Tech LLC](https://appshunter.io/developer/1567747524) | [Taiki Nishimura](https://appshunter.io/developer/1780302048) |

## What reviewers say

### π Challenge

[App page](https://appshunter.io/ios/app/challenge/id6743357759)

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

**In-app purchases:** none


### NBack³

[App page](https://appshunter.io/ios/app/nback-memory-training-game/id6745750227)

This brain training app uses the scientifically proven Dual N-Back method to enhance cognitive functions like working memory, focus, and decision-making. It offers adjustable difficulty levels and tracks progress with a visually engaging interface.

**Highlights:** Dual N-Back method, Adjustable difficulty (n=1-5), Enhances working memory, Improves inhibitory control, Develops attention skills, Progress tracking, Streak bonus system

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| プレミアムプラン | $0.49 | per month |


## Frequently asked questions

### Is π Challenge free?

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

### Is NBack³ free?

NBack³ is free to download, with in-app purchases available.

### Do π Challenge or NBack³ have ads?

NBack³ shows ads; π Challenge does not.

### Which is updated more often, π Challenge or NBack³?

π Challenge ships an update every 9 months, and NBack³ every 4 days. Most recently, π Challenge was updated on September 24, 2026 and NBack³ on August 14, 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.*