Decaff: Caffeine Sleep Tracker

About

Decaff shows you one number that matters: how much caffeine is still in your body right now, and when it will drop low enough for you to sleep. Log a coffee, tea, energy drink or cola in two taps. Decaff draws your caffeine curve for the day, works backwards from the bedtime you chose, and tells you your last call: the latest time you can still have a coffee and stay under your sleep threshold tonight. HOW IT WORKS • Pick the time you want to be asleep and how sensitive you are to caffeine. • Every drink you log updates a live decay curve for the day. • Before you drink, Decaff previews what that drink will leave in your body at bedtime, so you can decide with the numbers in front of you. • One last call reminder a day. No marketing, no nagging. LOG IN SECONDS Espresso, latte, filter, cold brew, tea, energy drink, cola, pre workout or a custom dose. Three sizes, and a quick log row with the drinks you use most. Logged the wrong thing? Remove it with one tap. BUILT AROUND YOUR CHEMISTRY Set your own half life, bedtime and sleep threshold. Sensitivity profiles for normal, sensitive and pregnancy adjust the math for you. PRIVATE BY DESIGN Everything is computed on your phone. No account, no servers, nothing uploaded. Apple Health integration is optional: write the caffeine you log to Health, and read your sleep to compare nights. DECAFF+ Upgrade for the full picture: • Trends: daily totals, a heatmap of when you caffeinate, and your last call streak. • Sleep correlation: with Health access, compare how long you sleep on nights you stayed under your threshold versus nights you did not. • Smart last call notification: a single reminder, recomputed every day from what you actually logged, with a lead time you choose. • Sensitivity profiles: normal, sensitive and pregnancy presets, plus manual half life tuning. • History export: download your full log as CSV. Decaff provides estimates for general wellness and is not a medical device or medical advice. Privacy Policy: https://docs.google.com/document/d/18ztnxOoF2-2GGkEHo5bm6XuNcyk_OHCfR_8ZMb8Aqew/edit?usp=sharing Terms of Use: https://docs.google.com/document/d/1Jk7q7-BvnKQF5jKhG3pq1zJzqr_Nu6Dy-rI8MSJT21I/edit?usp=sharing