Track your stress on Apple Watch.
Lumi turns the HRV your Apple Watch already records into a clear, all-day stress level — plus a daily recovery score, sleep, and breathing exercises to bring you back down. No extra gear, nothing to press.
Everything your stress is telling you
Lumi listens to the signals your Apple Watch already collects and turns them into something you can act on.
Stress from your Apple Watch
Lumi reads the heart-rate variability (HRV) your Watch records all day and overnight, and turns it into a clear stress level — hands-free, with no test to run.
A daily recovery score
One number for the day — your Excellent Day score — built from overnight HRV and recovery, so you know when to push and when to rest.
Breathe and reset
Guided breathing — box, 4-7-8, belly and more — designed to bring your heart rate down in about a minute when stress spikes.
Sleep, steps & daylight
Lumi folds in sleep, activity and time in daylight from Apple Health, so your stress score always has real context.
Water & caffeine
Log hydration and caffeine in a tap and see how they nudge your stress, sleep and energy over time.
On your wrist & Home Screen
A Watch app and widgets keep your score a glance away. Your health data stays in Apple Health, on your device.
See Lumi in action
Your stress, recovery and heart data — on iPhone and right on your wrist.
How to monitor stress on your Apple Watch
Set-up takes about a minute. After that, Lumi works quietly in the background.
- Get LumiDownload it free from the App Store and tell Lumi a little about your routine.
- Wear your Apple WatchKeep it on through the day and overnight so it can capture HRV, heart rate and sleep.
- Lumi reads your signalsIt pulls HRV and sleep from Apple Health automatically — nothing to press, no manual test.
- See your score each morningWake up to your stress and recovery score, and watch the pattern build over weeks.
Your health stays on your device.
Stress is personal. Lumi reads from Apple Health on your iPhone and Apple Watch and keeps your data on your device — no account needed to start. See exactly what the app does, and doesn't, in the Privacy Policy.
Questions people ask
Short answers, honestly given.
How do I monitor my stress on Apple Watch?
Lumi reads the heart-rate variability (HRV) your Apple Watch records through the day and overnight and turns it into a simple stress level. There is no test to run: wear your Watch, and Lumi updates your stress and daily score automatically from Apple Health.
What is HRV, and how is it related to stress?
HRV is the small variation in time between your heartbeats. When you are calm and recovered it tends to be higher; under stress or fatigue it tends to drop. Lumi uses your Watch's HRV to estimate how much stress your body is under and how well you are recovering.
Do I need an Apple Watch to use Lumi?
Yes. Lumi's stress and recovery scores are built from the HRV and sleep your Apple Watch measures, so a paired Apple Watch is required for the core experience. You can still log water, caffeine and breathing exercises on iPhone alone.
What is the daily Lumi score?
It is a single number that sums up your day — your Excellent Day score — based mainly on overnight recovery and HRV. A high score means you are well recovered; a lower one is a nudge to take it easier. It is designed so you can compare days and follow the trend.
How does Lumi measure my stress during the day?
As your Apple Watch records HRV samples, Lumi reads them from Apple Health and maps them to a stress level, so you can see your calm and tense stretches across the day without doing anything manually.
Is my health data private?
Your health data is read from Apple Health and kept on your device, and you do not need an account to start using Lumi. Only anonymous, aggregated analytics help improve the app; you can read exactly what is collected in the Privacy Policy.
Can Lumi help me calm down?
Yes. When stress climbs, Lumi's guided breathing exercises — box breathing, 4-7-8, belly breathing and more — are built to bring your heart rate down in about a minute. Over time you can see how a session affects your numbers.
Does Lumi track sleep, steps and hydration too?
Yes. Alongside stress and HRV, Lumi brings in sleep, steps and daylight from Apple Health and lets you log water and caffeine, so your stress always has context.
Is Lumi a medical device?
No. Lumi is for wellness and informational purposes only and does not diagnose, treat or prevent any condition, including anxiety or any medical disorder. If you are concerned about your stress or health, please talk to a qualified professional.
Which Apple Watch and iPhone does Lumi need?
Lumi runs on iPhone with iOS 18 or later and a paired Apple Watch on watchOS 10 or later. It works best when you wear your Watch overnight so it can capture your sleep and recovery.
Know your stress. Take control.
Wear your Apple Watch tonight and wake up to your first Lumi score tomorrow.