LightnFast

Fast simply. See progress.

Free · In‑App Purchases

Track fasts on your schedule, review your history, and see your progress clearly. Fast simply. See your progress clearly. LightnFast is a focused intermittent fasting tracker for iPhone and Apple Watch. Start a fast now or from a recent scheduled time, then follow a clear timer and an elapsed-time fasting-stage timeline. Choose a 16:8, 18:6, 20:4, OMAD, or custom plan, set your eating window, pick fasting days, and decide whether fasts start or end automatically. Review past fasts in a calendar and detailed history. Record clean, dirty, completed, or early-ended fasts; add daily goals, bedtime, and notes; and see streaks, outcomes, weekly completion, and all-time totals. Statistics separate days fasted from fasts finished. Optional notifications can mark a reached goal, a closing eating window, a scheduled start, or an elapsed-time stage change. Permission is requested only after you choose notification controls in Settings. A Live Activity keeps an active fast visible on the Lock Screen and Dynamic Island. Optional Home Screen and Lock Screen widgets show the current fast or next scheduled start. With Apple Health access, LightnFast can show weight and body composition, show sleep onset context, save weight you enter, and mirror supported water goals. On Apple Watch, start or end a fast from the wrist and see the current timer in complications. Choose optional iCloud sync for fasting plans, history, goals, daily records, saved bedtime entries, and notes. Notification preferences sync separately. Weight and body-composition reads stay on device; a saved bedtime entry may sync as part of a daily record. Unsynced records can be lost when you delete the app or replace your device. Pro includes LightnFast Home and Lock Screen controls, optional Health-powered progress experiences, and the Apple Watch companion. Fasting stages use typical timings from small studies. Your timing depends on your last meal, activity, and metabolism. LightnFast measures time, not your biology. It does not provide medical advice. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://yishanhe.net/lightnfast/privacy

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

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    Information

    Seller
    Shanhe Yi
    Size
    9.4 MB
    Category
    Health & Fitness
    Compatibility
    Requires iOS 18.0 or later.
    • iPhone
      Requires iOS 18.0 or later.
    • Apple Watch
      Requires watchOS 10.0 or later.
    Languages
    English and 8 more
    • English, French, German, Japanese, Korean, Portuguese, Simplified Chinese, Spanish, Traditional Chinese
    Age Rating
    16+
    In-App Purchases
    Yes
    Copyright
    © 2026 Shanhe Yi
  • Developer Website
  • Privacy Policy

    • Supports

    • Family Sharing

      Some in-app purchases and subscriptions may be shareable with your family group when Family Sharing is enabled. Learn More

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