Features — StayFasted | See What's Inside

🧠 Coaching

It's 2 AM. You're about to break. Open the app.

You tap "Hungry." You write "really craving pizza right now."

Most apps would say "Keep going!" and leave you alone with your willpower.

StayFasted reads your mood, checks what hour you're in, and responds:

"That hunger is fuel switching. At 23 hours, your body isn't running out. It's adjusting. Ketones are rising. This wave passes in 20 minutes."

It knows you. Because everything, the AI, your notes, your "why", lives on your phone. Not on a server. Not behind a paywall. Just yours. On devices with Apple Intelligence (iOS 26+), responses use on-device AI. On earlier versions, you get our built-in coaching engine with the same personalized approach.

AI coach responding with personalized fasting guidance

🔬 Body Science

"Why do I feel like this at hour 18?"

Because your liver just ran out of glycogen and your body is switching to fat for fuel. Ketones are flooding your bloodstream. Your brain is adjusting to a new energy source.

That's not a guess. That's Stage 4 of 8.

StayFasted tracks your fast through 8 biological stages, from Fed State to Immune Reset. Each stage tells you what's happening inside, what you might feel, and what to do about it.

When you know the headache at hour 14 is temporary and means ketosis is starting, you stop panicking and start trusting the process.

8 fasting stages with completion checkmarks

💬 Check-Ins

"How are you doing?" Not "how many calories?"

Every few hours, the app asks how you're feeling. Not what you ate. Not your macros. How you're doing.

Tap an emoji: 💪 Strong. 😌 Okay. 😐 Hungry. 😤 Tough. 😞 Low. Add a note if you want.

The app responds based on where you are in your fast. At hour 12 feeling hungry, you get science. At hour 36 feeling low, you get your own mantra back.

After a few fasts, you start seeing patterns. "I always struggle at hour 20 but feel great by 24." That self-knowledge is worth more than any calorie counter.

Check-in with mood emojis and personal notes

⏱ Timer

Built for the 72-hour faster, not just the 16:8 crowd.

Every fasting app has a timer. Most of them were designed for daily intermittent fasting. Try a 48-hour fast on those apps and you get... a big number ticking up. No context. No milestones. No guidance.

StayFasted shows you your percentage of goal, your current body stage, calories tracked, and upcoming milestones. It supports 16:8, 18:6, 20:4, OMAD, 24h, 36h, 48h, and 72h protocols.

At 33% of a 72-hour fast, you can see you've entered Fat Burning mode. At 50%, you'll unlock Autophagy. The timer becomes a map, not just a clock.

Timer showing 33% of 72-hour fast with stage info

🍲 Refeed

You finished your fast. Now what?

This is the part nobody talks about. You just fasted for 48 hours. You feel incredible. You open the fridge and eat a massive meal.

Twenty minutes later: cramps, nausea, regret. Your digestive system wasn't ready.

StayFasted walks you through it step by step. Start with liquids. At +2 hours, light foods. At +6 hours, whole foods. At +12, you're back to normal. It tells you exactly what to eat, what to avoid, and why.

No other fasting app does this. They end at "fast complete." We keep going because the refeed is part of the fast.

Step-by-step refeed guide for safely breaking a fast

💧 Hydration

That headache at hour 14? Probably not hunger. Probably water.

Most fasting discomfort comes from dehydration, not hunger. Your kidneys excrete more water when you fast. Electrolytes drop. The "fasting flu" kicks in.

StayFasted tracks your water, coffee, and tea with one-tap logging. It knows black coffee won't break your fast and doesn't make you feel guilty for drinking it.

Quick-add buttons for 8, 12, 16, or 24 oz. A daily goal ring that fills as you drink. Built right into your fasting flow, not a separate app you'll forget to open.

Water tracking with quick-add and beverage types

✨ And More

Everything you need. Nothing you have to rent.

The free tier gives you a fasting timer with every protocol, 8-stage body science, check-ins with AI coaching (3 per day), and hydration tracking. That's more than most apps charge $70/year for.

Upgrade to Lifetime and unlock everything: unlimited AI coaching, schedule your next fast, weekly rhythm planner, 28-day adherence grid, fasting journal, body measurements, supplements, analytics, achievements, Apple HealthKit, refeed guide, and CSV export.

$99 one-time. $49.50 with code EARLYBIRD. One payment. Yours forever. No subscription. No renewals.

50 lifetime spots. When they're gone, it moves to subscription pricing.

14 features organized into Planning, Tracking, Insights, Nutrition, Personal sections

Privacy

Your data never leaves your phone.

No account. No cloud. No analytics tracking your meals. StayFasted runs 100% on-device. Your fasting data, your AI conversations, your check-in notes exist on your iPhone and nowhere else.

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On-Device AI

Apple Intelligence only

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No Account

Nothing to sign up for

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100% Local

Delete app = delete data

See what's inside StayFasted.