Klyft is a consumer health platform that unifies data from every major wearable — Apple Watch, Garmin, WHOOP, Oura and Fitbit — into a single daily score across recovery, nutrition and fitness.

Most people who wear a fitness tracker today end up with multiple dashboards and scores that contradict each other, with no clear guidance on what to actually do day to day. Klyft sits above those wearables as the intelligence layer, turning raw data into one specific decision: what to train, what to eat, when to recover, when to back off.

The core output is the Arc Score — a 0-100 daily metric blending sleep quality, training load, recovery readiness and nutrition balance. A weekly longevity score called Meridian sits alongside, built from nine wearable-native signals including cardiorespiratory fitness trajectory, sleep regularity, heart rate variability, heart rate recovery and circadian rhythm integrity.

The architecture is deliberate. The scoring engine is fully deterministic and grounded in over 800 peer-reviewed studies in exercise physiology, sleep science, chronobiology and nutrition. AI is used only for the parts that benefit from language — daily coaching through an assistant called Lumen, conversational meal analysis and workout generation — never for scores or health claims. This is not a wrapper around an LLM. It is a scientific engine with an AI coaching layer on top.

Core features

• Multi-wearable unification with Apple Watch, Garmin, WHOOP, Oura and Fitbit. One profile, one timeline, one score.

• Arc Score: a daily 0-100 health score across recovery, nutrition and fitness, derived from a deterministic engine grounded in peer-reviewed research.

• Meridian: a weekly longevity score built from nine wearable-native signals tracking cardiorespiratory fitness, sleep regularity, HRV, HRR, circadian rhythm and nocturnal respiratory rate.

• Lumen AI coach: translates each day's calculated numbers into specific, contextual recommendations on training, nutrition, sleep and recovery.

• Conversational meal logging: log a meal by typing a description or photographing the plate. The AI identifies food items, estimates portions and produces a full macro and micronutrient breakdown.

• Adaptive workouts: AI-generated workouts that auto-regulate to current recovery state, training history and goals.

• Holistic insights: real-time understanding of how sleep, training, nutrition and recovery influence each other, not four siloed metrics.

• Privacy: data is encrypted in transit and at rest, never sold to third parties, and handled in line with GDPR.

Built for people who already train hard and already wear the devices — runners, lifters, hybrid athletes, Hyrox and CrossFit competitors. The audience is data-aware, time-constrained, and tired of apps that treat fitness like a video game.

Live on the iOS App Store with a free tier and a Pro subscription. Longer-term, the same intelligence layer extends beyond training and recovery into broader longevity — combining wearable data, biomarker intelligence and behavioural science into a unified health operating system.