Start a fast and the ring fills in real time. Close the app, restart your phone — it picks up exactly where you left off, because Metabo counts from when you started, not while it's open.
Why it's different
A fasting timer that's accurate, honest, and yours.
Most fasting apps look the part but lose your timer on a restart, hide the science, and quietly mine your data. Metabo was built to fix exactly those three things.
A timer that survives anything
Metabo stores when you started, not a running counter. Quit the app, reboot, swap phones — your fast resumes to the exact second, every time.
Real metabolic stages
Watch yourself move from Fed to Fat burning, Ketosis and Autophagy — each stage clearly explained, so you understand what's happening, not just a number.
Private by design
Sign in with Apple, sync through your own private iCloud. No third-party trackers, no data resale — your fasting history is yours alone.
The science, made visible
Know exactly what your body is doing.
As the hours pass, Metabo moves you through the real stages of a fast — and tells you what each one means.
🍽️
Fed
Blood sugar rises as you digest your last meal.
0–4h
🔥
Fat burning
Glycogen runs low — fat becomes the main fuel.
4–12h
⚡
Ketosis
Ketones rise for steady, even energy and clarity.
12–16h
✨
Deep ketosis
Fat-burning peaks; many feel sharp and light.
16–24h
♻️
Autophagy
Cells begin to recycle and repair themselves.
24h+
Everything you need
Beautifully simple, genuinely useful.
A focused set of tools that respect your time and your attention.
Live fasting ring
Start, track and end your fast with a ring that fills to your goal in real time.
Streaks & insights
Day streak, weekly chart, completion rate, longest fast — your momentum at a glance.
Learn library
Plain-English guides on how fasting works, what breaks a fast, and beating hunger.
Plans that fit you
16:8, 14:10, 18:6 or 20:4 — pick a window and change it anytime.
Gentle reminders
Know when your eating window opens and when it's time to fast again.
Yours, privately
Sign in with Apple and sync across devices through your own private iCloud.
Built for people who want fasting to feel calm and clear — not another app that loses the timer and sells the data.
Private by design. Sign in with Apple, your own iCloud, no third-party tracking. Just your fasts, your devices, your progress.
Pricing
Start free. Go deeper with Premium.
The core timer and your streak are free, forever. Metabo Premium unlocks every plan, the full stage science, deeper insights and the Learn library.
Free
$0
Always free · no ads
Live 16:8 fasting timer
Day streak & basic history
Current fasting stage
Private iCloud sync
METABO PREMIUM
Premium
$39.99 / year
≈ $3.33/mo · cancel anytime
Every plan — 16:8, 14:10, 18:6, 20:4
Full stage timeline & Learn library
Advanced insights & weekly charts
Reminders & data export
✓ Start free. Restore Purchases always available.
Metabo Premium is an auto-renewing subscription billed to your Apple Account at confirmation. It renews at $39.99/year unless cancelled at least 24 hours before the period ends; manage or cancel anytime in App Store settings. Prices shown in USD and may vary by region.
Questions
Good to know.
Is Metabo free?
Yes — the fasting timer, your history and the metabolic stage view are free. Premium adds deeper analytics, custom fasting protocols and unlimited history.
Does the timer survive a restart?
Yes. Metabo stores your fast's start time, not a countdown, so closing the app, restarting your phone or running out of battery doesn't lose your progress.
Which fasting protocols are supported?
16:8, 18:6, 20:4, OMAD, 5:2 and custom windows you define yourself.
Where is my fasting data stored?
In your own private iCloud and on your device. We don't run a separate analytics server that profiles you, and we never send your fasting details to third parties for marketing.
Does it ask to track me across other apps?
No. Metabo uses no third-party advertising and no cross-app tracking, so there's no ATT prompt.
Is this medical advice?
No. Metabo is a wellness and tracking tool, not a medical device. Talk to a doctor before starting any fasting protocol, especially if you're pregnant, diabetic or have a history of disordered eating.