Cortex: AI Focus Timer

Cortex is a focus timer for deep work and study — Pomodoro 25/5, Long Focus 50/10, Short Sprint 15/3, an open-ended Flow mode, 19 ambient tracks and a sleep timer.

Built for people who think for a living: students revising for exams, developers and designers in deep work, writers, and anyone with ADHD who needs sound and structure to get started.

Four timer modes, three focus sounds, session history, streaks, heatmaps and Apple Health are free. Premium adds the AI Adaptive mode, 16 more sounds, the sleep timer, custom presets, Health Insights and the weekly report. No ads, no account, no sign-up.

You track your workouts. Your sleep. Your macros. But not your focus. Cortex closes that gap: it measures your sessions, sizes the next one around your recovery, and shows you the hours your attention actually peaks.

STRUCTURED FOCUS MODES
Pomodoro (25/5) — Classic deep work intervals
Long Focus (50/10) — Extended sessions for complex tasks
Short Sprint (15/3) — A low-friction way to start on a bad day
Flow Mode (no limit) — Open-ended, stop when you are done
AI Adaptive (Premium) — Session length set for you, not guessed
Custom Timers (Premium) — Your own work rhythm, up to 10 presets

AI ADAPTIVE TIMER (PREMIUM)
Instead of asking how long you can concentrate, Cortex works it out. With Apple Health connected it reads your heart rate variability and last night's sleep; without Health it falls back to a time-of-day model. Keep finishing your sessions and it extends them.

19 AMBIENT TRACKS
Focus: lo-fi beats, acoustic, downtempo, neo-classical, space ambient, cinematic, chillwave, jazz hop, deep pulse, ethereal piano.
Sleep: ethereal pads, deep drone, analog wash, submarine, harp lullaby, binaural, distant choir, zen garden, zero gravity.
Three focus tracks ship inside the app and are free. The other 16 come with Premium and download on demand, Wi-Fi recommended. Audio keeps playing with the screen locked.

SLEEP TIMER (PREMIUM)
Six durations from 15 minutes to 2 hours. Sound fades out gradually and stops — no alarm at the end. A morning check-in records how you slept and whether you woke up rested; with Apple Health connected, the sleep screen also shows last night's stages and a sleep score.

DATA, NOT FEELINGS
Focus Score — weekly performance metric
Peak Hours — the hours your attention actually peaks
Heatmaps — focus patterns across the