CaffeineHalf: Caffeine Tracker

Bedtime Half-Life Calculator

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

See how much caffeine is still in your body at bedtime. Plan your next cup, get Last Call reminders, and check your level from widgets, Apple Watch and Siri. 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/

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New: Apple Health integration, iCloud sync, Home Screen widgets, Apple Watch app, Siri and Shortcuts, bedtime notifications, water tracking, weekly and monthly trends, sip duration, and AI caffeine estimates for homemade drinks (iOS 26 or later with Apple Intelligence).

Version 1.0.4

The developer, Takumi Sekiguchi, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Used to Track You

    The following data may be used to track you across apps and websites owned by other companies:

    • Identifiers
    • Usage Data

  • Data Linked to You

    The following data may be collected and linked to your identity:

    • Identifiers
    • Usage Data
    • Diagnostics

  • Data Not Linked to You

    The following data may be collected but it is not linked to your identity:

    • Location
    • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

Accessibility

The developer has not yet indicated which accessibility features this app supports. Learn More

Information

Seller
Takumi Sekiguchi
Size
10.2 MB
Category
Food & Drink
Compatibility
Requires iOS 16.0 or later.
  • iPhone
    Requires iOS 16.0 or later.
  • iPad
    Requires iPadOS 16.0 or later.
  • Mac
    Requires macOS 13.0 or later and a Mac with Apple M1 chip or later.
  • Apple Vision
    Requires visionOS 1.0 or later.
  • Apple Watch
    Requires watchOS 9.0 or later.
Languages
English and 14 more
  • English, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Portuguese, Simplified Chinese, Spanish, Thai, Traditional Chinese, Turkish, Vietnamese
Age Rating
4+
In-App Purchases
Yes
Copyright
© 2026 Small App Works
  • Developer Website
  • Privacy Policy

    • More by Takumi Sekiguchi