Caffeine: Track Caffeine Decay

App details — Caffeine: Track Caffeine Decay A calm, science-based caffeine tracker that shows you exactly how much caffeine is still in your bloodstream and when it'll be safe to sleep. The problem it solves : Most people know caffeine affects sleep but have no concrete sense of how much is still active in their system at bedtime. "Don't drink coffee after 2pm" is generic advice that ignores individual Caffeine: Track Caffeine Decay variation, dose size, and timing. Caffeine: Track Caffeine Decay replaces the guess with a number. Core mechanic : Average adult Caffeine Decay is ~5 hours but genuinely ranges 3–7 hours based on genetics (CYP1A2 enzyme activity), liver function, pregnancy, smoking, and other medications — so it's a user-adjustable setting, not a hardcoded constant. That's the credibility hook: this isn't a vague wellness app, it's applying a real model correctly. Feature list : Live decay curve on Home One-tap quick-add (espresso/coffee/energy) Full drink-log sheet, 6 presets + custom mg "Safe to sleep by X" message 7-day intake bar chart Cutoff calculator (last safe coffee time) Personal half-life slider (3–7 hrs) Sleep-safe threshold Push reminders CSV export Dark mode