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Burn tracks your fast and names the stage you are in as you cross it, so the hours mean something while you are living them.
It is built for iPhone, iPad, and Apple Watch by an independent team, and it is designed to be the fasting app you keep rather than the one you download twice.
9
named stages, Fed State to Deep Autophagy
21
guided programs, plus three of your own
6
support tools, one tap from the timer
0
calories to count or meals to photograph
No calorie database, no meal photographs, no macro grid. One question: when did you stop eating?
Fed State through Deep Autophagy, each one telling you what is happening and how firm the evidence behind it is.
Native iPhone, iPad, and Apple Watch, with Apple Health, widgets, Live Activities, and Siri.
Most fasting apps count down. Burn tells you what the count means.
Hour eight is not hour sixteen. Your body works through its easy fuel first, then starts releasing stored fat, then shifts again. Burn names the stage you have reached, tells you what usually comes next, and tells you how long it typically lasts.
It also holds the parts of fasting that a timer normally leaves out: the support tools for when hunger arrives, the record that shows a habit forming, and the daily read that turns your own history into something useful.
The measure we hold every feature to is whether it makes the fast easier to follow. If it does not, it does not ship.
How we build it
These decide what goes into the product and what stays out of it.
01
Burn maps elapsed time to named stages. It does not claim to measure ketosis, autophagy, or your metabolic state, and it tells you which claims rest on firm evidence and which are still being studied.
02
Fasts are not lost at hour one. Burn puts six support tools one tap from the timer, for the twenty minutes that decide a fast.
03
Apple Health is optional. Export everything to CSV whenever you want. Nothing is collected that the app does not use.
04
Twenty-one programs, nine stages, and a full library sit behind one screen with a start button on it. Depth is there when you want it and out of the way when you do not.
Who Burn is for
If you want a bare timer, plenty exist and they are free. Burn is for people who want the hours explained, want help when a fast gets difficult, and want a record that shows whether any of it is working.
It suits a first 12:12 as well as a practiced 20:4. Twenty-one guided programs, seven quick plans, and three custom protocols cover most ways people actually fast.
Who makes it
Burn is made by WraithBit, Inc. and was founded by Jack Morton, who leads its product direction, design, development, positioning, and growth.
Being small is the reason the product stays focused. Every feature has to answer the same question before it ships: does this genuinely make fasting better for the person using it?
Read Jack's story →What Burn is, and where it stops
Burn measures elapsed time and maps it to named stages. Stage boundaries are the app's model, not a reading taken from your body.
Insights and Morning Brief report patterns in your own record. They are not a medical assessment, and Body Score is a Burn product score.
If you are pregnant or breastfeeding, have a history of disordered eating, manage diabetes, or take medication timed with food, speak to a clinician before fasting.
Burn is not a medical device and nothing in the app is medical advice. Science pages carry their own sourcing, recorded in dated evidence packets. Read the science section →
Finish dinner, hit start, and Burn will name every stage you cross between now and lunch.
Download free on the App StoreiPhone, iPad, and Apple Watch. Requires iOS 18 or watchOS 11.