Caffeine Health

Caffeine Health is a beautifully designed Android app that helps you understand how your caffeine intake affects your body throughout the day — and whether that late-afternoon espresso might cost you sleep tonight.

Log drinks from a curated catalog, watch your active caffeine level in real time on a 24-hour curve, and get a personalized sleep forecast based on your unique metabolism.

Features:

• Real-time 24-hour caffeine curve with emoji drink markers
• Personalized pharmacokinetic modeling based on age, weight, lifestyle
• Sleep forecast — see if caffeine will affect your bedtime
• Curated drink catalog: coffee, tea, energy drinks, soda
• Barcode scanning, live or from a photo, with an optional Open Food Facts lookup
• Typo-tolerant drink search and tea re-steep tracking
• Drink detail sheets showing individual contribution curves
• Quick actions — edit, duplicate, or delete entries
• Analytics: caffeine by source, bedtime impact, and when you drink it, hour by hour
• Home screen widgets, reminders, and automation via Tasker, MacroDroid or NFC tags
• Material 3 Expressive design with dynamic color
• Montserrat typography and haptic feedback throughout
• Full dark mode support

Privacy:

• Works fully offline — all your data stays on your device
• The internet is only used if you choose to look up a scanned barcode on Open Food Facts, and only the barcode number is sent
• No ads, no tracking, no telemetry, no accounts
• Open source (GPL-3.0)

Science:

The app uses a one-compartment oral pharmacokinetic model with personalized half-life calculation. Your caffeine metabolism is estimated from age, weight, smoking status, alcohol intake, and CYP1A2-inhibiting medications — grounded in real pharmacology.