CaffeineHalf: Caffeine Tracker

Track your caffeine and see an estimate of how much will still be in your body at bedtime. CaffeineHalf uses a pharmacokinetic half-life model (5 hours by default, adjustable to your own body) to draw your remaining caffeine curve and tell you when it drops below your threshold. FEATURES - Remaining caffeine at bedtime, with a time-decay curve graph - Estimated time your caffeine drops below your set threshold (50 mg by default) - Plan your next drink: preview how one more cup changes tonight's level - Auto-calculate caffeine from drink type, plus custom drinks - AI estimate of caffeine in your own homemade drinks (iOS 26 or later on devices with Apple Intelligence available) - Daily caffeine limit with progress - Personal half-life and sensitivity, set during first-time setup - Sip duration: absorption accounts for how long you take to finish a drink - Water intake tracking - Weekly and monthly trends and your most-consumed drinks - Apple Health: write your intake, and read sleep and heart rate for correlation insights - iCloud sync across your devices - Home Screen widgets: remaining-caffeine curve and quick add (iOS 17 or later) - Bedtime notifications: Last Call reminders and limit alerts - Apple Watch app - Siri and Shortcuts to log or check your caffeine, plus URL scheme support GREAT FOR - People sensitive to caffeine's effect on sleep - Anyone improving their sleep routine - Timing coffee and energy drinks around work and study - Managing intake during pregnancy or nursing Goes beyond simple intake counters by predicting the caffeine actually remaining. Estimates are for reference and are not medical advice. Your caffeine records are stored on your device. If you are signed in to iCloud, your records, saved drinks and settings are also stored in your own iCloud and synced automatically between devices using the same Apple Account; the app has no separate sync switch. FREE VERSION AND FULL ACCESS The free version displays banner ads. The free version shows your last 7 days of history and lets you keep 1 saved custom drink and 1 next-drink plan per day. Full Access adds unlimited history, saved drinks and plans, plus CSV export of your history. A one-time Full Access purchase unlocks every feature and removes ads. Customers who previously bought the paid app also continue without ads. Privacy Policy: https://smallappworks.com/caffeinehalf/privacy/ Support: https://smallappworks.com/caffeinehalf/support/