You already wear the sensor. Apple Watch records heart rate, HRV, sleep and activity all day. The problem is that the Health app shows those numbers one by one, and they don't answer the question you actually have in the morning or at 15:00: do I have energy for this?
Metrya on Apple Watch puts that answer on your wrist, with a complication on your watch face so you don't even need to open the app.
What's on the Watch
The app is a vertical stack of pages. Scroll with the Digital Crown.
Pages follow your iPhone dashboard. If you hide Thermal or Caffeine on the phone, they disappear from the watch too. Free users never see locked pages: Pro pages simply aren't there.
Why Reserve Is the Star of the Watch
On the iPhone, Reserve is a chart of your day so far. On the wrist it is a live gauge. It starts each morning from your recovery and then drains while you are awake and active, and refills a little during real rest.
Between phone syncs, the watch keeps Reserve moving with its own fresh samples, so it doesn't look frozen at the last number your iPhone sent. The next time the iPhone syncs, the two line up again.
Two Clocks, Always Labelled
Some numbers on the watch are read live from the watch's own Apple Health data: heart rate, steps, last night's sleep, overnight HRV, resting heart rate, wrist temperature and the food you logged. Others are calculated on your iPhone and sent over: Recovery and biological age.
The app never mixes the two up. Live values are marked as live on the wrist. Values from the phone show when the phone last calculated them. If the watch has no data yet, it says so, for example "Waiting" for Recovery, instead of inventing a number.
Complications
| Complication | Shows | Watch face slots |
|---|---|---|
| Reserve | Your live energy Reserve | Circular, corner, inline |
| Reserve + Recovery | Reserve from the wrist and this morning's Recovery from the phone | Rectangular |
What the Watch App Deliberately Doesn't Do
- It doesn't record workouts. You already have the Workout app, Strava or Garmin for that. Two apps recording the same run creates duplicate sessions. Metrya reads your workouts from Apple Health afterwards and gives each one a heart-rate curve, zones and training load.
- It doesn't log meals. Logging happens on the iPhone. The watch shows the result.
- It doesn't run the AI. Questions and reports live on the iPhone, where there is room to read the answer.
- It doesn't use GPS.
Privacy on the Wrist
The watch talks to your iPhone and reads Apple Health on the watch. No health data goes to a Metrya server, because there isn't one that accepts it. Base features need no account and no subscription. Read more on how Metrya keeps health data on your devices.
Who It's For
- People who want a Whoop- or Garmin-style energy number without buying another device. See Whoop alternatives for Apple Watch.
- People who check readiness before a workout and don't want to open three apps.
- Sauna and cold-plunge users who want to time a plunge without their phone near the water.
Put your Reserve on your watch face.
The Metrya Watch app comes with the iPhone app. The core pages and complications are free, and your health data stays on your iPhone and watch.
Download Metrya Free