Correlate turns the Apple Watch you already wear into daily readiness, recovery, strain, and sleep scores. No ring, no strap, no monthly fee. Nothing leaves your iPhone.

The 20-second journal is there so the app can ask a real question: did late caffeine wreck last night's sleep? Did a hard run lift tomorrow's HRV? It waits 14 days before claiming a pattern. Correlation, not causation.

Features

Recovery, Strain, and Sleep rings, plus Health Score, Body Battery, Stress Load, Daylight, and Biological Age
Auto-discovery of correlations (Pearson r), including delayed effects up to 7 days
Official Oura and WHOOP export import — parsed on-device, no account linking
Daily briefing and "ask your data," generated on the iPhone
No accounts, no cloud, no tracking. Health access is requested only after you pick the questions you want answered

One-time purchase on the App Store — $4.99. No subscription.