WHOOP's band is included with membership, but the membership itself runs $199–$359/yr depending on tier — and the band stops working the moment it lapses. Kreev works with the Apple Watch already on your wrist, and the free tier keeps working no matter what.
Hardware + subscription, year one. No hidden fees.
Kreev: free to start, Sentinel $39.99/yr — no hardware required. WHOOP: $199–$359/yr membership, band included — no separate hardware charge.
WHOOP pricing per whoop.com/membership, as of Sept 2026 — re-check before publishing, WHOOP has changed tiers twice in the past year.
| Feature | Kreev | WHOOP |
|---|---|---|
| Additional Hardware Cost | $0 — uses the Apple Watch you own | $0 — band included with membership |
| Subscription | $5.99/mo or $39.99/yr | $199–$359/yr depending on tier |
| Commitment | Cancel anytime | Annual membership; the band stops working when it lapses |
| Works with Apple Watch | ✓ Yes | ✕ No |
| Recovery Score | ✓ | ✓ |
| Personal Baseline (Z-Score) | ✓ | ✕ Population average |
| Algorithm Transparency | Published | Black box |
| Plain-Language Insights | Daily narrative, generated on-device | Coaching tips |
| Free Tier | Yes | ✕ |
| Trial | 1-month Sentinel App Store trial | ✕ |
| Data Privacy | Kreev's watch app can't even read Apple Health — your iPhone computes your scores and sends only the finished numbers to your watch, over Apple's own encrypted connection | Standard policy |
WHOOP's band comes with membership, but the band stops working the moment membership lapses — an annual commitment in practice. Kreev uses the Apple Watch you already own, and the free tier keeps working no matter what.
WHOOP benchmarks your recovery against population data. Kreev uses Z-score statistics against your own rolling history — so your score reflects how you are doing compared to your normal.
WHOOP gives you a number without showing its work. Kreev publishes its methodology and generates a plain-language narrative every morning, on your iPhone, explaining exactly why your score is what it is.
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