CoreFast is a calm intermittent fasting tracker that keeps your data on your phone. Pick a plan, tap Start, and see where your fast is at a glance.
No account. No ads. No surprise charges.
Ending a fast early is recorded neutrally, never as a failure.
Today and plans
• A live timer that stays accurate if you close the app or go offline
• Daily plans from 12:12 to 23:1, plus 5:2, alternate-day, Sunrise to sunset and a custom plan
• Each plan explains what a day on it looks like before you switch
• Water tracking with your own daily goal
• Optional local reminders, with quiet hours
• Optional streaks with a weekly rest day, and challenges you choose to join
• Longer fasts come with a short sheet on what to expect and when to stop
Food log (optional)
• Log what you eat during your eating window
• Scan packaged foods by barcode (you can turn this off in Settings)
• See calories that other apps log to Apple Health
Health readings (optional)
Connect Apple Health to see last night's sleep, steps, active calories, resting heart rate, HRV and glucose next to your fast. CoreFast only reads; it never writes to Apple Health. Vitals shows your readings over 7 days, 30 days or all time, compared only with your own usual range, and a summary you can share if you choose. Readings are shown as recorded, not as an assessment.
Insights and Learn
Trends, history and a month calendar show how your fasts have gone. Week on week compares you only with yourself. Learn has 18 short reads in plain language, each with a link to its source. New to fasting? For your first four weeks, Today shows one short tip a day.
Circles (optional)
Fast alongside a few friends. Share your status, send a cheer, or run a group challenge, like Sugar free or a water goal, with a shared leaderboard. Updates are encrypted and pass through a relay that keeps them for up to 24 hours. Your fasting history and health readings are never sent.
Widgets, Watch and Siri
• Home Screen, Lock Screen and StandBy widgets; fast details stay hidden while your iPhone is locked
• A Live Activity and Dynamic Island countdown
• An Apple Watch app with one-tap End and Undo
• Siri, Shortcuts, and Controls for Control Center, the Lock Screen and the Action button
Private by design
Your fasts, food log, water and health readings stay on your device, stored encrypted. They are never sent to us or to any server. If you turn on barcode scanning, only the barcode number is looked up, at Open Food Facts. No account, no ads, no third-party analytics or tracking. Your location is used only if you choose the Sunrise to sunset plan, and is kept on your phone. Export a backup or spreadsheet whenever you like, or delete everything from Settings.
A note on safety
CoreFast is a tracking tool for general wellness. It is not a medical device and does not give medical advice. Fasting isn't right for everyone: talk to your clinician before you start, especially if you are pregnant, take medicines for diabetes, or have a history of disordered eating. Stop and eat if you feel unwell. A few private questions at the start can switch CoreFast to simple time logging, a quieter app with no streaks or longer plans.
Questions or feedback: corefast.support@icloud.com
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