# NBack 3D vs Random Quiz

The clearest difference is in-app purchases: Random Quiz at none against NBack 3D's 1. Random Quiz also leads on update cadence (every 5 days vs every 10 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. NBack 3D sells 1 one-off in-app purchase. Random Quiz asks for nothing beyond the download.

NBack 3D ships an update every 10 months, Random Quiz every 5 days. The most recent releases landed on October 20, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | NBack 3D | Random Quiz |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/nback-3d/id1407606652/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | Every 10 months | **Every 5 days** |
| Monetization | Free with in-app purchases | — |
| Size | 5 MB | 3 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) | [Katsuhiko Yao](https://appshunter.io/developer/1543188534) |

## What reviewers say

### NBack 3D

[App page](https://appshunter.io/ios/app/nback-3d/id1407606652)

This app challenges your memory by requiring you to count 3D shapes of specific colors. As the 'N' value increases, the difficulty escalates, testing your ability to recall past stimuli in a sequence.

**Highlights:** N-Back memory challenge, 3D shape and color recognition, Increasing difficulty levels, Sequence memorization, Cognitive skill enhancement

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Extend to 20'Back & Remove Ads | $2.99 | one-time |


### Random Quiz

[App page](https://appshunter.io/ios/app/random-quiz/id6744266408)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is NBack 3D free?

NBack 3D is free to download, with in-app purchases available.

### Is Random Quiz free?

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

### Do NBack 3D or Random Quiz have ads?

Both NBack 3D and Random Quiz show ads.

### Which is updated more often, NBack 3D or Random Quiz?

NBack 3D ships an update every 10 months, and Random Quiz every 5 days. Most recently, NBack 3D was updated on October 20, 2026 and Random Quiz 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.*