Cortex Brain Trainer: N-Back

Cortex is an offline brain-training app: dual N-Back, a Stroop test, Schulte tables, a reaction time test and an RSVP speed reader, plus Sudoku, Nonogram and Word Search puzzles. No account, no internet, no tracking: nothing leaves your phone. Also known as: n-back memory test, Stroop effect test, Schulte grid, reflex test, speed reading trainer. Seventeen focused brain games and classic puzzles, plus Peak Hours: a personal cognitive instrument you won't find in other brain trainers. Four games are free forever; unlock all seventeen plus Peak Hours with a single purchase. No subscription, no ads, no accounts, and nothing leaves your device. PEAK HOURS A quick reaction check you can take any time of day. Over time it charts when your mind is sharpest and reveals whether you're a morning lark, a night owl, or steady all day. Fully private, stored only on your phone. THE GAMES Memory, focus, reading, timing and spatial skills, each built around a real task: - N-Back, Sequence Memory and Remember-To for memory - Stroop, Track and Peripheral Vision for attention - Schulte Table and Speed Reader for visual scanning and reading - Mental Rotation for spatial reasoning - Inner Clock for your sense of time - Number Sequences for pattern reasoning SKILL DRILLS - Mental Math: learn a real trick, then drill it - Speed Math and Estimation for arithmetic fluency and number sense CLASSIC PUZZLES - Nonogram: solve the number clues to reveal a hidden picture - Sudoku and Word Search, as pure puzzles FREE TO START, UNLOCK ONCE Four games are free forever: N-Back, Stroop, Schulte Table and Speed Math. Unlock all seventeen games plus Peak Hours with a single one-time purchase. No subscription, no ads, no renewing charges. PRIVATE BY DESIGN No accounts, no analytics, no advertising, no third-party trackers. The app works fully offline and your stats stay on your phone. Privacy here isn't a setting you switch on; it's how the app is built. BUILT FOR FOCUS A precision design made for concentration, not a candy-coloured slot machine. Make it yours with multiple themes, light or dark, and a custom accent colour. Track your personal bests at your own pace. Now fully available in nine languages.