Dual N-Back - 脳トレ

⏺ 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.