Luen

Modern life is quietly dismantling your health. You sit all day, sleep too little, rarely see sunlight, and carry stress that never resolves. The cruelest part? You don't feel it happening. The feedback loop is broken.
But your body has been keeping score the entire time.
VO2 Max and Resting Heart Rate are among the strongest reflections of cardiovascular fitness which itself is among the strongest predictors of how long and how well you'll live. They don't cause longevity. They reflect whether you're living in a way that produces it.
Luen reads these signals from your Apple Watch and connects them to four daily habits: exercise, sleep, daylight, and stress. No logging. No manual input. You live your life. Luen shows you what your body thinks about it.
What you'll see
Your VO2 Max and Resting Heart Rate trends over time
How your four key habits: workouts, sleep, sunlight, stress - track day by day
Weekly consistency patterns and percentile changes
A clear, honest picture of your cardiovascular fitness trajectory
What makes Luen different
All analysis happens on your iPhone - your data never leaves your device
No account required. No social features. No ads
One-time purchase. No subscriptions. Ever.
Luen doesn't coach you. It doesn't gamify your health. It doesn't nag. It gives you something more durable than motivation: clarity. Once you see the connection between what you do today and how your body responds, you don't need an app to tell you what to do. You already know.
Requires iPhone with iOS 18+ and Apple Health data from Apple Watch.