# Dual N-Back - 脳トレ

> Dual N-Back - 脳トレ (iPhone/iPad app by Takanori Horitsu.)

- Source: https://appshunter.io/ios/app/dual-n-back/id6767109556 (this page in markdown: same URL + `.md`)
- Developer: [Takanori Horitsu](https://appshunter.io/developer/1896386009)
- Category: Education, Health & Fitness
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.6 · 10 MB
- Languages: English, Japanese
- Released: 2026-05-08
- Data updated: 2026-06-14
- User reviews in markdown: https://appshunter.io/ios/app/dual-n-back/id6767109556/reviews.md

## What is Dual N?

⏺ Train working memory in 5 minutes a day. Make brain maintenance a habit, like brushing your teeth.

  Dual N-Back is a science-based working memory trainer based on Susanne Jaeggi's 2008 paper "Improving fluid intelligence with training on working memory" — optimized for stress-free daily use on iPhone.

  ■ Built for you if

  - You feel your focus has been slipping
  - You want to maintain memory as you age
  - You've quit other brain trainers (too hard / too gimmicky / didn't stick)
  - You want a 70-second session that fits in any pocket of time
  - You prefer quiet consistency over flashy gamification

  ■ Key Features

  【Science-Based Training】
  The Dual N-Back task — comparing visual position and audio cues simultaneously to N positions ago — is one of the most-studied paradigms in cognitive training (100+ peer-reviewed papers). This app implements the original task faithfully.

  【Around 70 Seconds Per Session】
  20 trials × 3.5 seconds, finishable on the train, at lunch, or before bed. We don't recommend long sessions — once daily is enough for measurable effect.

  【Auto-Adjusting N Level】
  The N level (2-9) auto-tunes based on your last 3 sessions' scores. The AI keeps you at "just above your limit" — sustainable challenge for the long haul.

  【3 Game Modes】
  - Focus: Standard 20-trial session
  - Challenge: Maximize consecutive correct answers
  - Endless: No time limit, full immersion

  【19 Achievement Badges】
  "First Play", "7-Day Streak", "Reach N=5", "90% Accuracy" and more. Badges naturally surface progress without nagging push notifications.

  【Privacy First】
  All scores and history stay on your device. No server transmission, no tracking. Fully Apple Tracking Transparency compliant.

  ■ About Ads

  The free version includes a modest banner ad. Upgrade to Premium (one-time purchase) to remove all ads.

  ■ Optional In-App Purchase

  "Ad-Free" is a one-time $1.99 purchase. Not a subscription, no renewal forgetting. The free version is fully functional.

  ■ Devices

  iPhone (iOS 17+)

  ■ Languages

  Japanese, English

  ■ Privacy Policy / Terms

  https://hori2-t.github.io/dual-nback-legal/

  ■ Contact

  Feedback and bug reports welcome via App Store reviews or GitHub Issues.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Ad-Free | $0.99 | one-time |



## Version history (last 3 releases)

### 1.2.1 — 2026-05-27

Fixed an issue where streak records could disappear after updating. Improved data migration to preserve existing user progress.

### 1.1 — 2026-05-12

- Pause feature added — pause and resume a session at any time
- Button corrections now possible — press again to deselect a wrong input

### 1.0 — 2026-05-08

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-14.*