The most honest intermittent fasting timer on iOS. Pick your protocol, start your fast, get notified when you're done.
Free to start · $2.99 one-time for Pro · No subscription
Features
Built to be the last fasting app you'll download.
Animated progress ring shows exactly where you are in your fast — down to the second. Persists across app restarts.
16:8, 18:6, 20:4, and OMAD — each with difficulty guides so you start at the right level. Custom hours for Pro users.
Know when you enter fat burning, ketosis, and autophagy. Real science, no fluff — displayed right on the timer.
Every fast logged automatically. See your weekly completion rate, average fast length, and current streak at a glance.
Opt-in push notification when your fast is complete. No nagging, no marketing — just the one alert you actually want.
All data stays on your device. No account. No cloud sync. No analytics. Nothing leaves your iPhone.
Screenshots
Dark, minimal, and fast — exactly the way a utility app should feel.
Live timer
Protocol picker
Fast history
One-time purchase
Science
PureFast shows your current metabolic phase in real time — not just a timer.
Your body is digesting your last meal. Insulin is elevated and glucose is your primary fuel.
Insulin levels start dropping. Your body begins transitioning away from glucose.
Glycogen stores are depleted. Your body switches to burning stored fat for energy.
Ketone production begins. Many people report improved mental clarity at this stage.
Maximum fat oxidation. This is the stage most 18:6 and 20:4 fasters are targeting.
Your cells begin recycling damaged components. A key mechanism behind longevity research.
Pricing
We charge once. You own it forever. No tricks, no renewals.
PureFast Pro
One-time payment · No subscription · No renewal
Free to download · $2.99 unlocks everything
Reviews
The most common feedback: "Finally — no subscription."
"I've tried Zero, Simple, and three others. They all switched to $70/year subscriptions. PureFast does everything I need for $2.99 total. That's it. No more searching."
marcus_fasts · App Store
"The phase tracker is surprisingly motivating. Seeing 'Fat burning' on screen when I'm hitting hour 9 makes me want to push through to 16. Clean, honest app."
healthymindset22 · App Store
"No account. No email. No data. Just a beautiful timer. I paid the $2.99 pro upgrade in about 3 seconds after opening it. Exactly what this should be."
TechMinimalist · App Store
Download now
No sign-up. No tutorial. Just open and tap start.
Free to download · $2.99 one-time for Pro · iOS 16+