Open the Health app and you see dozens of categories, each with its own chart. HRV was 42 ms. Resting heart rate was 58. You slept 6 h 51 min. Each number is correct. None of them answers the question you actually have: should I train hard today, or take it easy? Why am I so tired this week?
Those answers need several numbers read together, against your own normal. Metrya is an Apple Health companion app that does exactly that, on your iPhone.
What's Already in Your Apple Health
If you wear an Apple Watch, Apple Health probably has months or years of data like this:
| Data | Recorded by | What Metrya turns it into |
|---|---|---|
| Sleep and sleep stages | Apple Watch, Oura, other wearables | Night score, personal sleep need, 7-night sleep debt |
| HRV (SDNN) | Apple Watch, several times a day | Recovery, Stress Monitor, Sentinel |
| Resting heart rate | Apple Watch | Recovery, Sentinel, Reserve |
| Wrist temperature, breathing rate | Apple Watch (newer models), Oura | Sentinel's overnight check |
| Workouts with heart rate | Apple Watch, Garmin, Strava and others | Zones, training load, load ramp |
| Steps, active energy, daylight | iPhone and Apple Watch | Reserve drain, Output index, Net Energy |
| VO₂max, walking speed | Apple Watch, iPhone | Fitness trend, biological age, walking quality |
| Weight, body fat | Smart scales | Body report, BMI shown with context |
| Blood pressure | Connected cuffs, manual entries | Morning trend and what sat next to each reading |
Metrya doesn't need its own hardware. It works with anything that writes to Apple Health: Apple Watch, Oura, Ultrahuman, Whoop, Garmin, Amazfit and smart scales.
Four Questions, Answered Every Day
Always Against Your Own Normal
The most important idea in Metrya is the personal baseline. A resting heart rate of 62 is great for one person and a warning sign for another. So almost every score compares today with your last few weeks:
- Recovery compares HRV and resting heart rate with your 30-day baseline.
- Sleep debt uses a sleep need learned from your own nights.
- The Stress Monitor compares each HRV reading with your readings at the same time of day.
- Sentinel compares five overnight signals with your 28-night normal.
When there isn't enough history yet, the app says so, for example "6 of 10 nights", instead of showing a number it can't support.
Go Deeper When You Want To
- Sleep: a hypnogram with overnight heart rate, stage shares against your own 30 nights, and what shaped the night (training, caffeine, bedtime drift, alcohol).
- Training: heart-rate curve, zones, splits and what each session cost overnight.
- Stress and Sentinel: daytime strain from HRV, and an overnight early-warning signal.
- Weekly reports: your week ranked and read back to you. See reports.
- Nutrition (Pro): meals logged to Apple Health and read next to your nights. See nutrition.
- Blood pressure: cuff readings in context. See the blood pressure guide.
- Biological age and longevity: biological age and Longevity Signals.
Ask "Why?" in Plain Language (Optional)
With Pro, you can ask the Advisor questions like "why is my recovery low this week?" and get an answer that uses your actual numbers. You choose the model: Apple Intelligence, a model you download to the iPhone, or your own API key. The AI is a way to ask why. The scores above work without it.
Private by Design
Every score is calculated on your iPhone. There is no account, and Metrya has no server that receives health data. If you use a cloud AI with your own key, the request goes straight from your phone to that provider, and you see what is sent first. More on the privacy page.
Getting Started
Install Metrya, allow Apple Health access and open Today. The first sync reads your last 30 days, so if you've worn a watch for a while, most screens are ready on day one. Step-by-step instructions and common questions are on the getting started page.
Your Apple Health data, finally explained.
Metrya reads the data you already have and turns it into recovery, energy, sleep and training answers. Free to download, no account, everything calculated on your iPhone.
Download Metrya Free