Just Zones

Just Zones turns the workouts you already record in Apple Health into an honest, weekly picture of time spent in each heart-rate zone.

WHAT IT DOES
• Week view: time in each zone this week, compared with last week and your usual (median of your last 4 weeks)
• Every workout, in full detail: heart-rate curve, minutes per zone, histogram, best sustained heart rate over rolling windows, and zone-change count
• Runs and rides with GPS: route map coloured by heart-rate zone, with auto splits
• Effort and recovery: elevated-effort intervals and recovery phases inferred from your heart-rate curve, for any workout type
• Strength, swimming and 50+ other workout types each get the detail HealthKit actually provides — the app tells you plainly when Apple Watch doesn't record something (e.g. reps or weight for strength workouts), instead of guessing
• Zone model shown, not hidden: uses Apple's own recorded zones when a workout has them, otherwise a clearly labelled heart-rate-reserve (Karvonen) estimate — with the exact BPM bounds and inputs always visible
• Manual zone settings: adjust max heart rate, resting heart rate, LTHR and age yourself if you don't want the app's estimate

TRENDS (PRO)
See your last 30 days of trends for free — weekly intensity mix, when you train, and more. Just Zones Pro extends Trends to your full history — one-time purchase, Family Sharing included, no subscription. Everything else in the app — Week, every workout at any age, and sharing a workout as an image — stays free, always.

PRIVACY
Just Zones reads workouts and heart-rate data from Apple Health — read-only, it never writes anything back. Your health data is processed and stored on your device. The app has no accounts and no backend of its own. It sends anonymous crash reports and handles purchases through third-party services; your health data is never included in either.

REQUIREMENTS
Requires an iPhone with workout and heart-rate data in Apple Health — recorded by Apple Watch, the Workout app, or another app that writes to Health. Just Zones does not record its own workouts and has no Apple Watch app.