Intermittent fasting for iPhone and Apple Watch
Do IF times your fast and shows which stage your body is likely in. Water, weight and movement live in the same app. Open it and you know what to do next. No sign-up needed.
* Except the AI coach and AI food check, which send data only when you tap to ask
Highlights
The ring changes color across 7 body stages. Slide to start or stop, so no accidental taps.
No need to grab your phone. The ring on your watch changes color with each body stage, just like on iPhone.
The Today screen gives you one clear nudge. Tap it and it's done.
The bottle follows the time of day, so you see the gap without doing math.
The coach sees a summary of your fasting, water, weight and sleep. Snap a meal and the AI estimates calories and protein, then suggests what to eat next.
Stored on your phone, encrypted. Face ID lock, no ads.
Shown as a likely range, never one promised date, and tracked for you.
While you fast
The timer ring changes color across all 7 stages. Tap one to see what may be going on.
0h
Your body is digesting your last meal. Blood sugar is still up.
4h
Insulin starts to fall and stored energy comes into play.
8h
Glycogen stored in your liver becomes the main fuel.
12h
Your body tends to lean more on fat for energy.
16h
Your liver may start making ketones. Some people feel less hungry.
18h
Longer fasts may help clear out old cells.
24h
Drink enough water. Stop right away if you feel unwell.
Times are rough estimates and vary from person to person, depending on your last meal, sleep and activity.
Every feature, in depth
Today
Open the app and get one clear nudge for right now, like "time to start your fast" or "you're behind on water". No digging through tabs.
IF timer
Pick your plan and let the app keep count. Your fast shows up wherever you look on your iPhone.
Water & meds
The bottle shows where you should be by now for the time of day, so you see exactly how far behind you are.
Body & weight
Set a goal and the app estimates when you'll likely get there, as a range, not a single promised date. Then it keeps an eye on whether you're on track.
Period log Silver
Log it on the Today screen. The app predicts your next period, reminds you before it and tells you when you may feel hungrier.
Ovulation days are estimates only. Never use them for birth control.
Workouts
The goal the World Health Organization recommends. Log workouts yourself or pull them from Apple Health.
Apple Watch Silver
No need to grab your phone. The ring on your watch changes color with each body stage, just like on iPhone.
AI coach Gold
The coach sees a summary of your fasting, water, weight and sleep, so the answers are about you, not generic advice.
Midnight Gold Gold
Navy and gold across the app, Lock Screen, widgets and Apple Watch. The fasting ring glows, with a slow light running along it.
Silver comes with the Moonlight Silver theme too
Friends & sharing
It's easier to keep going when someone's cheering you on. Add friends by QR code or play online.
Friends see progress numbers only. Never your weight, body data or anything from Apple Health. Your name stays hidden until you turn it on. Share cards never include weight or waist size.
And more
99 levels. Earn XP for fasting, water and weigh-ins. Your medal changes every 10 levels, and at level 99 you become a Legend and can start again.
Miss one day a week and your streak stays alive. With Silver you can pick days off and set a different plan for each day.
Every finished fast on one calendar, so you can see how the month went.
New Year, Lunar New Year and Songkran looks, with special app icons.
One tap while fasting, free. Silver shows which hours of your fast you get hungriest.
See whether sleep, water or start time helps you finish more fasts. Worked out on your phone (Silver).
Progress photos stay on your phone. Never sent to our server, never sent to AI (Silver).
What improved and what to try next. Worked out on your phone, on any plan.
Set buttons for the bottles you really use, log a whole bottle in one tap, and pick how your bottle looks (Silver).
Start a fast or add water without opening the app (Silver).
A 24-hour dial, a body-stage ring and a fasting path, 3 designs in all (Silver).
Take everything out as CSV files on any plan. It's your data.
The app tells you to slow down, and suggests electrolytes if you're fasting. On every plan.
Plans go up to 16:8 only, and the AI coach is for ages 18 and up.
The app reminds you to eat enough and shows your goal as a range, never pushing you to lose faster.
Settings → Privacy & data → Delete all app data. If you have an account, it asks whether to delete that too.
Privacy
The app works fully without sending your health data anywhere. No ads, and we don't make money from anyone's data.
Read the full privacy policyDownload and go. An account is only for online friends, or the AI coach and AI food check.
Your data lives on your iPhone and can't be read while it's locked. Moving phones? It comes along with iCloud Backup.
On from the start, and the screen is hidden in the app switcher so nobody sees your weight.
No third-party analytics or ad SDKs. Delete everything with one button.
A summary of your data or your food photo goes to Anthropic's Claude only when you tap to ask, after you agree separately. Our server doesn't store your messages or photos, and we ask again if the terms change.
Plans
Bronze covers all the everyday basics. No ads, no time limit. The deeper insights live in Silver and Gold.
Bronze
Free
No ads, ever
Silver
14-day free trialor
Everything in Bronze, plus
Gold
or
Everything in Silver, plus
AI food check (photo, text, next meal) shares 90 uses a month · AI needs you to be 18+, signed in, and to agree first · AI answers are general guidance, not medical advice
Silver Lifetime
Early Bird · first 300 onlyPay once and keep everything in Silver forever. No renewals. Want the AI coach? Add Gold anytime. Leave Gold and you still have Silver.
Early Bird price for the first 30 days after launch · then
Paid through the App Store, cancel anytime in your iPhone's Settings · The free trial is for Silver only, for people who haven't tried it before. If you don't cancel before it ends, billing starts automatically · Silver Lifetime is a one-time payment and doesn't renew · Prices shown are for Thailand and may differ in your country; the price in the app is the one that applies.
Intermittent fasting is safe for most healthy adults, but talk to a doctor first if you:
Stop right away if you feel unwell. If you're very dizzy, have a racing heart, feel faint or confused, drink water, eat something, and see a doctor if it doesn't get better.
Do IF helps you track and get reminders. It isn't medical advice and isn't meant to diagnose or treat any condition.
Help
Yes, it's free, and no account is needed. The timer, water, weight, hunger log, workouts and med reminders are all in Bronze, with no ads. Insights like charts beyond 30 days, body measurements, before-and-after photos and Apple Health sync are in Silver.
iPhone with iOS 18 or later. The Apple Watch app is part of Silver. There's no Android version yet.
Your data lives only on your phone. It comes back if you restore your new phone from iCloud Backup or a computer backup. Apple Health data follows your Apple ID. You can also save a copy first with Settings → Privacy & data → Export my data.
Open Settings → Health → Data Access & Devices → Do IF and turn everything on. For other brands, turn on Apple Health syncing in that watch's own app first (reading from Apple Health is part of Silver).
Cancel in your iPhone's Settings → your name → Subscriptions. On a new phone, open the app and go to Settings → Restore purchases.
On your phone. Never stored on our server, never synced to iCloud or put in your iPhone Calendar, never on share cards. It's included in your iPhone backup if iCloud Backup is on. If you have Gold and ask the AI coach, the app sends a short period summary too, but never ovulation days. Lock Screen reminders use neutral wording, so anyone glancing at your screen won't know what it's about. Ovulation days are estimates from your logged periods and must not be used for birth control.
In the app, go to Settings → Privacy & data → Delete all app data. If you have an account, it asks whether to delete your online account too. This can't be undone.
Timer, water, weight and movement, all in one place. No ads, your data stays on your phone, and it's free from day one.
Coming soon to the App Store.
