Apple Watch · HealthKit · iOS

Know Your
Recovery.

Your Apple Watch already tracks your health. Kreev turns that data into a personal Recovery Score — based on your body, not a population average — so you know exactly how you're doing each morning.

$0 Hardware · $3.33/mo · Your Baseline, Not Theirs
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25 spots · 14 days · Complete the program → earn 6 months of Sentinel free

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Be first to know when we launch in May 2026.

Coming to the App Store

Launching May 2026.
Free 30-day trial, no card required.

$0 Hardware Uses your Apple Watch
Personal Baseline Compared to you, not averages
Open Algorithm We show our math
Privacy First Your data stays yours

One Number.
Your Entire Day.

Every morning, Kreev analyses your overnight biometrics — heart rate variability, resting heart rate, sleep quality, activity load, respiratory rate — and distills them into a single Recovery Score from 0 to 100. Not a guess. Not a population average. A precise reading of how your body recovered, compared to your own history.

75–100
Excellent High readiness — your body has recovered well
60–74
Good Moderate readiness — a normal day
40–59
Fair Below baseline — consider lighter effort
0–39
Low Recovery deficit — rest and recuperation observed
0 RECOVERY
62ms HRV
52bpm RHR
7.8h Sleep
8,420 Steps

Your Score Compares You to You.

Most wellness apps compare you to population averages — norms built from studies that may not reflect your age, fitness level, or physiology. Kreev is different. It builds a rolling baseline from your own recent history and measures how today deviates from your normal. An elite athlete with a resting heart rate of 42 bpm and a weekend jogger at 72 bpm both get scores that reflect their individual recovery — because the reference point is always you.

01
Wear

Your Apple Watch collects heart rate, HRV, sleep, steps, respiratory rate, and VO2 Max throughout the day and night.

02
Baseline

Kreev builds a rolling average of your recent 7–60 days. This is your personal normal — unique to your body.

03
Score

Each morning, today's metrics are compared to your baseline using Z-score statistics. The result is your Recovery Score.

Seven Signals. One Picture.

Every metric has a story. Kreev reads them all.

Stress Index
The inverse of recovery. When your body is under strain, this number reflects how much physiological load your system is carrying. Tracked daily against your personal baseline.
0%
LOW
Resting Heart Rate
0 bpm
Your heart's resting efficiency. Lower trends signal improving cardiovascular fitness.
Heart Rate Variability
0 ms
The variation between heartbeats. Higher HRV correlates with better autonomic recovery.
Sleep Duration
0 hrs
Total sleep versus your baseline. Consistency indicates more than one good night.
Steps / Activity
0
Daily movement load. Kreev tracks whether activity is adequate — or pushing too hard.
Respiratory Rate
0 br/min
Breathing rate during sleep. Subtle changes can signal shifts in recovery status.
VO2 Max
0 ml/kg/min
Peak oxygen uptake — your aerobic ceiling. Tracked over months to measure fitness trajectory.

See it in the app

Kreev app — Recovery Score dashboard
Kreev app — Biometric metrics view
Kreev app — AI wellness narrative
Kreev app — Stress Index and trends
Kreev app — Metric drill-down detail
Recovery Insight AI · Gemini
87 Recovery Score

Your recovery score of 87 reflects strong overnight restoration. HRV at 62ms is 14% above your 7-day baseline, suggesting effective parasympathetic rebalancing. Resting heart rate at 52 bpm aligns closely with your recent average. Sleep duration of 7.8 hours exceeded your typical 7.1 hours, with deep sleep comprising 22% of total duration — a favourable distribution. Activity load from yesterday (8,420 steps) was moderate relative to your baseline, providing adequate stimulus without excessive strain.

Your Score, Explained in Plain Language.

Every morning, Kreev generates a personalised narrative that explains exactly why your Recovery Score is what it is. Powered by Google Gemini, these narratives analyse your overnight metrics, compare them to your personal baseline, and describe the patterns in clear, analytical language. No medical jargon. No vague advice. Just your data, interpreted.

Anonymized data only — no names or identifiers are sent to AI

Google does not use your data to train or improve its models

You can request an explanation of any day's score

Unlock Your Full Autonomic Intelligence.

Kreev is free to explore. Sentinel gives you the complete picture.

Recovery Score

Your daily 0–100 readiness number, computed from 6 biometric signals compared to your personal baseline.

AI Narrative

Full daily analysis powered by Google Gemini — explains your score in plain, analytical language every morning.

Stress Index

Numerical stress percentage with sparkline trend visualization. The inverse of your Recovery Score.

VO2 Max & Fitness Age

Aerobic capacity tracking with ACSM percentile and biological age estimation over time.

Trends & History

Baseline stability charts, 90-day heatmap, and longevity markers across all your biometric signals.

Guardian Alerts

Push notifications when your recovery drops below your configured threshold — proactive pattern detection.

Full Drill-Downs

Z-scores, physiological position, analysis and compass tabs for every metric — every day, in full detail.

Free tier includes: raw health metrics, qualitative stress tier, 7-day trend view, and basic drill-downs. No credit card required. No time limit.

We Explain How Your Score Works.
No Black Boxes.

Most wellness apps treat their scoring algorithms as trade secrets. We believe you have the right to understand how your data is being interpreted. Kreev publishes its scoring methodology, names every company that touches your data, and gives you the tools to control, export, or delete everything.

Algorithm Transparency

Your Recovery Score uses Z-score statistics against your personal rolling baseline. We explain the methodology in our Terms of Service — no black boxes.

No Demographic Profiling

Your score doesn't factor in age, sex, or ethnicity. Every user is compared to their own history — not a population average.

No Ads. No Tracking.

We don't use advertising cookies. We don't sell your data. We don't share it with data brokers. Ever.

Your Rights, Documented

CCPA opt-out. MHMDA consumer health data rights. PIPEDA compliance. Algorithm explanation on request. Purge Vault for full account deletion.

Recovery Is Not Rest.
It's Strategy.

You train hard. You push limits. But the difference between progress and plateau isn't how hard you go — it's how well you recover. Kreev gives you the data to train smarter, sleep better, and understand the signals your body sends every day. Your baseline is your starting line. Your Recovery Score is the compass.

Start Your Free Trial

Free for 30 days. No credit card required.

Simple, Honest Pricing.

Try everything free for 30 days. No credit card required.

Free
$0
forever
 
  • Raw health metrics (RHR, HRV, Sleep, Steps, Resp)
  • Qualitative stress tier (LOW / MODERATE / ELEVATED / HIGH)
  • 7-day trend view
  • Basic metric drill-downs
Download Free

Available at launch

Best Value
Sentinel
$3.33/mo
billed annually — $39.99/year
or $4.99/month
  • Everything in Free, plus:
  • Recovery Score (0–100)
  • Full AI narrative (Google Gemini)
  • Stress Index with sparkline
  • VO2 Max & Fitness Age
  • Trends, History & 90-day heatmap
  • Guardian Alerts
  • Full drill-downs (Z-scores, all tabs, all periods)
Start 30-Day Free Trial

No credit card required during trial

Questions? We've Got Answers.

Your Recovery Score (0–100) reflects your body's readiness based on your personal baseline. It is computed from sleep duration, heart rate variability, resting heart rate, activity load, and respiratory rate — all compared to your own recent history using Z-score statistics. Scores above 75 indicate high readiness; below 50 suggests your body may benefit from more recovery time.
An iPhone running iOS 16 or later and an Apple Watch Series 4 or newer (watchOS 9+). Series 4 and above support all 6 biometric signals. Older Apple Watch models support basic metrics but lack respiratory rate and VO2 Max.
Kreev compares your metrics to your own personal baseline — not population averages. We publish our scoring methodology, name every company that touches your data, and offer algorithm transparency that no other wellness platform provides. Plus, there's no hardware to buy and no 12-month commitment.
No. Kreev is a personal health informatics tool. It provides analytical observations about your biometric patterns — not medical advice, diagnoses, or treatment recommendations. Always consult a healthcare professional for medical concerns.
The Stress Index (0–100) is the inverse of your Recovery Score. It reflects how much physiological strain your body is under. LOW (0–24), MODERATE (25–44), ELEVATED (45–64), HIGH (65–100).
Every morning, Kreev sends your anonymized metric values (no names or identifiers) to Google Gemini, which generates a plain-language explanation of your Recovery Score. Google does not use this data to train its models.
No. Kreev does not sell your data. We share data only with the service providers needed to operate the app (Google Cloud for hosting, Google Gemini for AI narratives, RevenueCat for subscription management). No advertisers, no data brokers.
Yes. In the app, go to Settings → Delete Account → Purge Vault. Type PURGE to confirm. This permanently deletes all health metrics, scores, narratives, and account data from our servers within 30 days. This action is irreversible.
Access to your raw health metrics, qualitative stress tier, 7-day trend view, and basic drill-downs. The Recovery Score, AI narrative, Stress Index percentage, VO2 Max tracking, Trends, History, and Guardian Alerts require a Sentinel subscription.
New users get 30 days of full Sentinel access — no credit card required. At the end of the trial, your account downgrades to the free tier. No data is deleted. You can subscribe at any time to restore Sentinel features.
We take privacy seriously. Read our Privacy Policy, Terms of Service, and Consumer Health Data Policy. We comply with CCPA/CPRA, MHMDA, and PIPEDA. You can opt out of automated scoring and request an explanation of any day's Recovery Score.
Contact us at support@kreev.app. You can also access the Help section within the app (Settings → Help).
Limited Beta · 25 Spots

Be One of the First
25 to Try Kreev.

Before we launch, we're inviting 25 Apple Watch users to test the app for 14 days. Complete the program and both feedback surveys, and we'll give you 6 months of Sentinel — completely free.

Apply for Beta →

Apple Watch Series 4+ · iPhone iOS 16+ · 18+

Start Understanding Your Recovery.

Free for 30 days. No hardware required. No credit card.

Requires iPhone with iOS 16+ and Apple Watch Series 4+