# NBack 3D vs ディアビアイ

The clearest difference is in-app purchases: ディアビアイ at none against NBack 3D's 1. ディアビアイ also leads on ads (none vs shown) and update cadence (every 8 days vs every 10 months). On price and device support there is nothing between them.

Both are free to download. NBack 3D sells 1 one-off in-app purchase. ディアビアイ asks for nothing beyond the download.

NBack 3D ships an update every 10 months, ディアビアイ every 8 days. The most recent releases landed on October 27, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | NBack 3D | ディアビアイ |
| --- | --- | --- |
| 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 | **No** |
| Update frequency | Every 10 months | **Every 8 days** |
| Monetization | Free with in-app purchases | — |
| Size | 5 MB | 55 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) | [TECH Planning LLC.](https://appshunter.io/developer/1604758659) |

## 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 |


### ディアビアイ

[App page](https://appshunter.io/ios/app/id6496848510)

**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 ディアビアイ free?

ディアビアイ is free to download, with no in-app purchases.

### Do NBack 3D or ディアビアイ have ads?

NBack 3D shows ads; ディアビアイ does not.

### Which is updated more often, NBack 3D or ディアビアイ?

NBack 3D ships an update every 10 months, and ディアビアイ every 8 days. Most recently, NBack 3D was updated on October 27, 2026 and ディアビアイ on October 21, 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.*