cernidia.
Get the free app

YOUR SIGNALS. YOUR EVERYDAY.

Understand your body.
Shape your day.

Sleep, recovery and energy make more sense together. Cernidia helps you understand your signals and find a next step that fits your day.

Download on the App StoreExplore Cernidia

Free · No subscription · No Cernidia account

MORE CONTEXT FOR YOU
Understand your recovery
Cernidia Readiness on iPhone with clearly labelled example data
Cernidia on Apple Watch with example signals
Make room for how you feel
App views use example data. Appearance may vary by version.
Your sources. Your choice.
Apple Health
Apple Watch
WHOOP
Connections are optional.

FROM NUMBERS TO CONTEXT

See what your day
is telling you.

Individual numbers are a starting point. Cernidia helps you see the picture behind them.

01 / SLEEP

Your night.
The bigger picture.

Understand available sleep records, explore your rhythm and see where recordings are missing.

Explore

02 / RECOVERY

Your baseline.
Your comparison.

Put suitable HRV and heart signals into personal context when enough readable history is available.

Explore

03 / ENERGY

A feel for
the day ahead.

Bring a cautious energy estimate together with your own check-in.

Explore

A LOOK INSIDE CERNIDIA

You don't have to
be a data person.

01

How was your night?

See available time asleep and the recorded timeline. Your next planned sleep window remains separate from the previous night's records.

How it works
Cernidia · Sleep · example view
Example data · not a personal assessment

MAKE IT FIT YOUR SETUP

Connect what you use.

Apple Health and WHOOP are optional sources. You choose which data to share.

Apple Health & Apple Watch

Use suitable sleep, heart and activity records from Apple Health, for example from your Apple Watch.

Explore
W

WHOOP

Connect your existing WHOOP account. Recovery, Sleep, Strain and Workouts remain labelled as WHOOP data.

Explore

Devices are sold separately. WHOOP requires its own membership. Features depend on your device, permissions and available records.

YOUR NEXT MEANINGFUL STEP

And then?
Make room for it.

Context becomes useful when you can do something with it. Give tasks, routines and recovery time a place in your day. Optional calendar access helps your plans fit around real commitments.

  1. 01

    Notice

    Look at your signals and add how you feel.

  2. 02

    Understand

    Consider the source, personal comparisons and limits.

  3. 03

    Choose

    Decide what fits you and your everyday life today.

Privacy

Personal.
Including your privacy.

Your health assessments and check-ins are created on your devices. No Cernidia account is required. Cernidia contains no advertising.

Optional WHOOP sign-in uses an online service. Cernidia contains no product analytics. The privacy policy explains data flows and limits.

Understand privacy

A LITTLE MORE UNDERSTANDING

Good questions.
Clear answers.

Explore all topics

Understand sleep

Make sense of the night behind your numbers.

Look at duration, rhythm and available stages together.

HRV & recovery

Your HRV needs your context.

Why your own baseline adds context that someone else's numbers cannot.

Everyday energy

How much fits into today?

What an energy estimate can tell you, and why it is not a measurement.

Apple Watch

Your signals, closer at hand.

How your iPhone, Health records and Watch companion work together.

Connect WHOOP

Your WHOOP data. Your day around it.

Connect Recovery, Sleep, Strain and Workouts with their source visible.

Smart Wake

A wake window you choose.

Understand the wake window and latest wake time before setup.

A few things to know.

Is Cernidia really free?

Yes. The current App Store listing offers Cernidia for free, without a subscription or in-app purchases. Apple Watch, WHOOP devices and any required WHOOP membership are separate offerings.

Do I need Apple Watch or WHOOP?

No. Tasks, routines and check-ins remain available without a wearable. Personal health assessments require suitable available records. Apple Health and WHOOP are optional.

What happens when data is missing?

Cernidia shows an unknown value or a learning state. Personal comparisons need enough suitable readable history. Missing values are not invented.

What does the energy estimate mean?

The Battery report is Cernidia's own calculated estimate. It is not a measurement of biological energy or a medically validated assessment.

Does Smart Wake detect my sleep stage live?

No. Smart Wake estimates a wake time from previously recorded sleep stages. Your latest chosen wake time is a backup. Alarm or notification permissions are required.

Is Cernidia a medical app?

Cernidia supports general wellness and everyday decisions. It does not diagnose conditions or recommend treatment. Medical questions belong with qualified professionals.

CERNIDIA

Your next step.
A little more informed.

Discover Cernidia for iPhone and Apple Watch.

Download on the App Store

Free · No subscription · No Cernidia account