Fasto — Intermittent Fasting

Fasto is an intermittent fasting timer that explains, hour by hour, what is happening inside your body — and shows you the study behind every claim it makes.

WHAT YOU WILL NOT FIND
No subscription. No in-app purchases. No ads. No account to create. No analytics and no trackers. And no servers of ours: your fasts live on your iPhone and, if you turn sync on, in your own iCloud. Never in mine. It works offline.

SCIENCE WITH ITS SOURCE ATTACHED
The eight metabolic phases cite the published work they rest on, with a direct link to PubMed so you can read it yourself. So does the guide on breaking your fast. And where the literature does not support a claim, Fasto does not make it: no miracle promises, no tidy numbers without evidence.

WHILE YOU FAST
• An animated ring with your progress, the phase you are in and a countdown to the next one.
• Eight phases from 0 to 72 h: stabilisation, glycogen, gluconeogenesis, early ketosis, full ketosis, autophagy, deep autophagy and immune renewal.
• Tips that change with the phase, a water counter, and an alert as each phase begins.

ON YOUR WRIST AND ON YOUR SCREEN
• An Apple Watch app to start and stop from your wrist, plus watch face complications.
• Home Screen and Lock Screen widgets with a button, without opening the app.
• A Live Activity in the Dynamic Island: your fast always in sight.

ON ALL YOUR DEVICES
Your fasts sync over iCloud between iPhone and iPad. No account and no servers of ours — it is your iCloud. Change phones and your history is still there. And on iPad it is not the iPhone app stretched out: it has its own two-column layout. Everything scales with Larger Text and works with VoiceOver.

WHEN YOU FINISH
A summary of what you achieved, the phase you reached, your personal record — and a guide on how to break the fast based on the hours you lasted, because coming off 14 h and coming off 30 h are nothing alike.

YOUR HISTORY, WITH INSIGHTS
Total, average and record, plus the patterns behind why you tend to stop, how each fast actually felt, and which durations suit you best. Milestones that add up and are not lost the day you slip.

YOUR MEASUREMENTS, NO VERDICTS
Log your weight and waist whenever you like and see how they change over 30, 90 or 180 days. Fasto shows the numbers and their variation, with no good-or-bad colours and no punishing streaks. The reading is yours and your doctor's.

TO TAKE TO YOUR DOCTOR
A PDF report with your period, frequency, adherence and longest fasts, ready to share. If your doctor is going to weigh in on your fasting, let them do it with data.

A PLAN FOR EVERY PACE
12:12, 14:10, 16:8, 18:6, 20:4, OMAD and custom. Forgot to hit start? Adjust the time whenever you like.

IN SIX LANGUAGES
English, Spanish, French, Italian, German and Brazilian Portuguese, switchable inside the app. Light theme, dark theme or follow the system.

ONE PAYMENT, FOR LIFE
You buy Fasto once and it is yours forever. Every feature and every future update is included. No premium tie