Track a fast, plan your week, and move one date without changing your routine.
FastZen tracks your fast and lets you move one date without rewriting your weekly routine.
Dinner running late? Adjust that day and keep the rest of your week. Preview the next 7 days, including start times, planned finishes and rest days.
• Start a 16:8, 18:6, 20:4 or OMAD (23-hour) fast.
• Set a custom duration from 1 to 48 hours.
• See elapsed time, remaining time and your planned finish.
• Review completed sessions and correct their times.
• Repeat one start time on the weekdays you choose.
Your active session stays saved when you close the app. No account, no ads and no server sync.
The widget puts your fast on the Home Screen. On iPhone, a Live Activity shows your session on the Lock Screen for up to 8 hours, the iOS limit. The session stays saved in the app.
FastZen is a tracking tool, not medical advice or a promise of weight loss.
Custom Week is a one-time purchase with no subscription. It unlocks a separate plan and start time for each weekday, rest days, and changes to a single date without changing your recurring week. People who used FastZen before version 1.1.0 keep that access without paying.
Ratings & Reviews
This app hasn’t received enough ratings or reviews to display an overview.
Fasting tracking features are unchanged in this version.
Version 1.4.1
The developer, Benjamin Dupin, 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 Not Collected
The developer does not collect any data from this app.
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