For people whose wearable shows the number but never the reason

Your wearable knows what happened. Bivryn tells you why.

“Why do I feel off today?” · “Is coffee wrecking my sleep?” · “Did that actually help?”

Most health apps wait for you to ask — log for a month, pick two things, run a correlation. Bivryn works the other way round. Every morning it reads your Apple Health stream — sleep, HRV, recovery, blood work, behaviour, weather — names what changed and the likely reason, and tells you whether what you tried last time actually worked. Oura, WHOOP, Garmin and lab panels flow in through Apple Health.

Get Bivryn How it works
Bivryn Home — body state hero with HRV and sleep narrative

No hypothesis required

You shouldn’t need a theory about your own body.

A tracker can tell you that two things moved together — once you’ve decided which two to compare and logged both for a month. Bivryn starts from the other end. It reads everything it already has access to, finds the pattern itself, and writes it as one sentence you can act on. No spreadsheet. No hypothesis. Thirty seconds in the morning.

Daily interpretation

"Your body is asking for a softer day."

Sleep debt and elevated overnight heart rate together — Bivryn names the contributors and suggests where to put your energy.

Lag pattern

"Hard workout Monday — HRV crash Wednesday is your 2-day lag pattern."

Bivryn now reads the 1, 2, and 3-day delays where the real signal often lives. The kind your wearable can't see in a single-day chart.

Recovery read

"Your HRV recovered fully — you're free to push."

Training capacity grounded in your own baselines, not a one-size-fits-all formula.

What Bivryn does

Built around one idea: your biology should make sense.

Today

A reading of your body, every morning.

Sleep, HRV, resting heart rate, recovery, respiratory rate, wrist temperature, training capacity, travel impact — synthesised into one calm sentence. The Arc behind it draws your last 24 hours and keeps going: a dashed forecast line through the rest of your day, with a one-liner naming the shape. Drag across it and each hour clicks under your finger. Tap anything to see the drivers, the numbers, and what could shift.

Bivryn Home — 'Your body is asking for a quieter day' with an unusual-overnight-pattern card
Why

Ask anything. Or ask nothing — it already looked.

Type a question — why am I tired this week, what changed about my last 14 days, does coffee affect my sleep — and Bivryn reads across your full year of biology, your logs, your weather and your patterns to answer. Three contextual follow-ups sit under every reply. But you never have to start: the morning reading already names the likely reason before you open the app. No chat-bubble feel. A calm editorial briefing on your own data.

Ask Bivryn — natural-language Q&A: 'why changes sudden in hrv' returns HRV, respiratory rate, and resting HR context
Patterns

Hidden patterns, surfaced over time. Now lag-aware.

Bivryn continuously finds correlations across your behaviour and biology — the kind you would never spot by hand — and now reads the 1, 2 and 3-day delays where the real signal usually lives. Each week it also scans new health research and surfaces only the findings that would change a decision about your own medications, supplements, labs or goals. Most weeks it ignores ten for every one it shows you, and it tells you the ignored count. The longer you stay, the sharper both get.

  • "HRV drops for 48 hours after alcohol."
  • "Hard workout Monday — HRV crash Wednesday is your 2-day lag pattern."
  • "Late dinners elevate overnight resting heart rate."
Discoveries — patterns Bivryn found in your data, with confidence bands and observation counts
Proof

Test what works on you. Get an honest answer.

Try one change at a time — a new supplement, an earlier dinner, a training protocol. Bivryn captures your baseline, tracks adherence, and tells you honestly whether your biology actually moved.

Experiment detail — adherence, baseline, and current metrics
Labs

Your blood work, interpreted.

Upload a lab PDF. Bivryn reads cholesterol, ferritin, vitamin D, hs-CRP, glucose, thyroid markers, hormones — connecting them to your sleep, energy, and recovery. Three lenses for hormone panels: cycle phase, mental-health context, and longitudinal drift.

Blood Work overview — markers with in-range dots and interpretation
Memory

Your body remembers. Bivryn tells you what it’s saying.

When today's biology matches a specific day from your own history, Bivryn surfaces what came next — the illness you were fighting off, the training block you started, the recovery that followed. Underneath it keeps a living timeline: travel, recovery stretches, supplement changes, training blocks, milestones. Six months from now you can look back and see what moved your biology and what didn't. Only possible with continuous years of your own data — the kind no single-year wearable can reach.

We've Seen This Before — today matched against May 23 with reasons: elevated resting HR and suppressed HRV
Long arc

Bivryn Bio Age — and a quarterly read on capacity.

A continuous biological-age reading composed from up to nine channels Bivryn can see — VO₂max, HRV, resting heart rate, walking heart rate, HR recovery, blood pressure, waist-to-height, sleep efficiency, and blood work when imported. Not a quiz: a living number scored against your own baselines and published healthy ranges, computed entirely on your device. Once a quarter Bivryn also picks a short set of physical tests matched to your age, biology, conditions and goals — grip, balance, mobility, endurance — so the number has something physical underneath it, tracked over years.

Bivryn Bio Age — chronological vs. biological readout in Body Memory
Right now

Evidence-backed resets for the moments you need them.

Five breathing techniques (coherent, box, 4-7-8, physiological sigh, alternate nostril). Mindful walks. Eye rest. Light reset. Bivryn measures the HRV delta before and after, so you see what's actually working for your nervous system.

Reset toolbox — breathing, mindful walk, eye rest, and light reset with HRV delta measured
On every Apple surface

Wrist. Lock Screen. Dynamic Island.

Glance at your wrist for your body state and recovery curve. Pin today's focus to your Lock Screen. Ask Siri, "why am I tired today?" or "can I work out?" — Bivryn answers in calm prose grounded in your real numbers. Run a Bivryn Shortcut from inside ChatGPT or Claude — the integrations are already there.

Apple Watch

Glance + complications

Widgets

Home + Lock Screen

Siri + Shortcuts

9 App Intents

Live Activity

Dynamic Island

Active experiment card + Lock Screen Live Activity

Privacy by default

Your biology stays on your device.

Bivryn doesn't sell your data. We don't share it with advertisers. Your biological signals live on your iPhone and (optionally) sync only to your own iCloud account. You can export everything, or delete everything, with one tap.

On-device

SwiftData + optional iCloud sync. Never sent to our servers.

Portable

Export everything as JSON, anytime, from Profile → Privacy.

Deletable

"Delete all my data" lives in the app. One tap, full wipe.

Shared on your terms

Share how you're doing with the people who care.

Optionally invite up to 5 people to see a calm summary of your biology — never raw numbers, never dashboards, just a read of how you're doing. Encrypted end-to-end through Apple's iCloud. Pause or remove any connection any time.

Read the full privacy policy →

Important

Bivryn is not a medical device.

Bivryn provides informational and educational insights about your biology. It is not intended to diagnose, treat, cure, or prevent any disease. For medical concerns, please consult a healthcare professional.

Extended trial

Want a longer look at Bivryn?

Drop your email. We'll send you an extended-access code that unlocks Bivryn beyond the standard trial — no subscription required.

Bivryn is on the App Store today with a 7-day free trial. These extended codes are for readers, reviewers, and users who want more time before deciding.

One email when your code is ready. No newsletter.

Ready when you are.

Bivryn is available for iPhone and Apple Watch. 7-day free trial, then $14.99 / month or $99.99 / year. Lifetime unlock available in-app.

What you'll see

Day 1
Body State — one calm reading of how your biology is landing today.
Day 7
First personal patterns emerge as Bivryn learns your rhythms.
Day 30
Discoveries + your first Long Arc — patterns worth naming.
Day 90
Body Memory speaks — years of biology become a story you can read.
Download on the App Store
QR code for Bivryn on the App Store
Scan on desktop
Opens the App Store

Requires iOS 17 or later. Apple Health and Apple Watch supported. Oura, WHOOP, and Garmin data flows in automatically through Apple Health.