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.