Nerivao: Sleep & HRV Tracker

I built Nerivao to answer one question every morning: what is different with me today – and what is that based on?

Nerivao reads your data from Apple Health, compares it with your own personal range and shows you in plain language what stands out. Every value shows where it comes from. When data is missing, Nerivao says "No data" – I don't fill gaps with made-up numbers.

SLEEP
• Sleep stages from your Apple Watch – REM, core, deep and awake – as a clear hypnogram
• Time asleep, time in bed, interruptions and your personal sleep goal
• Heart rate, HRV and respiratory rate during the night

RECOVERY & STRESS
• HRV, resting heart rate and other values compared with your own last 28 days instead of other people's averages
• Recovery and stress estimates based on your personal baseline – with an explanation of what contributes and how much
• An honest learning phase: estimates only appear once there is enough history

BODY & TRAINING
• Resting heart rate, HRV, respiratory rate, blood oxygen, wrist temperature, steps and energy – each with source and time
• Workouts from Apple Health with duration and optional perceived exertion
• Trends over 7, 30, 90 and 365 days

HOW YOU FEEL
• A quick check-in for energy, muscles, sleep feel and stress
• A journal with your own tags, such as caffeine or screen time – anything unanswered stays unknown
• Experiments: follow one habit and compare how things looked before and after

APPLE WATCH & WIDGETS
• Your daily summary on your wrist and on your Home Screen
• Apple Watch recommended, not required – Nerivao uses the data your devices record

PRIVATE BY DESIGN
• All calculations run on your iPhone
• No account, no health cloud, no cloud AI
• Read-only access to Apple Health; export or delete your entries at any time

Your feeling counts: if you feel tired on a "good" day, Nerivao records that instead of overruling you.

Nerivao is meant for fitness and wellness orientation. It does not diagnose any condition and is not a substitute for medical advice. If you have health concerns, please talk to a doctor.