Rekk

Rekk turns your Apple Watch data into one honest number each morning: your Body Charge. Every morning it reads your overnight HRV, sleep quality, resting heart rate, blood oxygen, respiratory rate, steps, sunlight and VO₂ max from Apple Health. It runs them through a scoring model built on longevity research (Huberman, Attia, Walker) to answer one question. How recovered are you today? BODY CHARGE The main number. Charged overnight by sleep and HRV. Drained by what you do during the day. Green means go. Amber means pace yourself. Red means rest. SCORED AGAINST YOU, NOT A POPULATION AVERAGE Most apps compare you to a fixed threshold. Rekk learns your own baseline over 30 days, so an ordinary night reads as ordinary whether your resting HRV is 35ms or 75ms. A good day for you is a good day. SLEEP Duration, deep and REM breakdown, efficiency, wake episodes and overnight heart rate. A rolling 14-night sleep debt figure tells you whether you are catching up or falling behind. INSIGHTS Trends for recovery score, HRV, resting heart rate, sleep, steps and sunlight, from 7 days out to 2 years. Plain-language observations when something in your data genuinely changes, not noise. TRAIN Log workouts with sets, reps and weight. Build reusable plans. See your previous performance on every exercise plus an estimated 1RM. Rest timer included. Your workout history backs up privately so you can recover it on a new phone. PRIVATE BY DESIGN Your health data stays on your device. Workout logs sync to a private cloud, and you can sign in with Apple to tie that backup to your account. No ads. No tracking. Your individual health records are never shared. FREE FOREVER No subscription. No paid tier. No feature held back. Everything in Rekk is free. Requires Apple Watch for HRV, sleep staging, SpO₂ and respiratory rate data.