FastDown
Pick a window. Hold the line.
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
A fasting countdown. Pick a window - 12 to 48 hours between meals, or any length you set - and hold the line.
Nothing is gated. Every window is pickable from day one; the ladder (12→18→24→36→48) marks progress, it doesn't lock it. Carry a window to term and it earns its badge and feeds a daily streak.
THE CLOCK RUNS FROM YOUR LAST MEAL, NOT FROM THE TAP. You eat, you remember the app an hour later. FastDown asks — one tap says when you actually started, and the timeline, badge and streak inherit the truth instead of the error.
WORKS WITHOUT BEING LOOKED AT. Start your usual window from a Home Screen widget, a notification button, or a Siri phrase. A Live Activity keeps the countdown on your lock screen, with a FINISH button once you're past term. Reaching term never stops the clock - overtime counts up, and the hours count.
IT LEARNS YOU, AND IT ASKS. Start at the same time five days running and it offers that time as your daily reminder. Skip every Sunday and it offers to keep the nudge quiet on Sundays. Give up 16-hour windows around hour nine three times and it offers a word of encouragement at hour eight-thirty. Every finding is offered once, your refusal is remembered, and nothing ever changes without your yes.
A RECORD YOU CAN TRUST. Every window is logged, finished or not. Entries can be corrected, past fasts added by hand, and a hand-logged fast is worth exactly as much as a timed one. Deleting is the only irreversible act in the app, so it gets an undo.
WHAT YOUR BODY IS DOING. A nine-stage timeline tracks the physiology of a fast — blood sugar, the glycogen tap, the fat switch, ketosis — hour by hour, wherever you are in the window. General information, not medical advice.
PRIVATE BY ARCHITECTURE. No account. Your record never leaves your phone. Anonymous usage counts help improve the app — nothing identifies you, and the switch to turn them off is in the open, on the main screen.
This is a timer, not medical advice. Fasting isn't for everyone - check with your doctor, drink water, and stop the moment you feel unwell.
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Your record now survives restarting your phone. After a restart, iOS wakes the app before the phone is unlocked, and FastDown could mistake that moment for a first run and start a fresh record over the old one. It waits for the unlock now.
WHAT EACH STAGE MEANS. Tap any row of the timeline while a window runs to read what that hour is, what the research shows, how settled it is, and where to read more.
The first card says what the app is, and the clock stops when no window is open.
The developer, Lobsag Paredes, 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 Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Lobsag Paredes
- Size
- 2.3 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- Copyright
- © 2026 L. Paredes