Caffy tracks your real-time caffeine level and predicts exactly when you'll be ready to sleep. Using science-backed caffeine half-life models personalized to your age, gender, sensitivity, smoking status, pregnancy, and more, Caffy visualizes your caffeine decay curve, sleep readiness score, focus window, AI-powered weekly insights, caffeine detox programs, and live widgets. Privacy-first, ad-free, no registration required, and available in 5 languages worldwide. Built for energy focus & sleep!