SparkFast vs StayFasted

Most fasting apps count hours. SparkFast shows you what those hours might mean — estimated biological milestones that give you a reason to keep going. THE SPARK CHART Your fasting hours aren't just numbers. The SPARK Chart visualizes five estimated biological processes — from early insulin changes to deep cellular recycling — based on published research. It transforms a blank timer into a roadmap of what you're working toward. GUIDED REFEEDING Breaking a prolonged fast matters as much as the fast itself. SparkFast provides step-by-step refeeding protocols tailored to your fast duration and dietary preference. No more Googling "how to break a 72-hour fast" mid-fast. AI-POWERED PERSONALIZATION Tell SparkFast about your goals, experience, dietary preferences, and schedule. Our AI creates a custom fasting plan built around your life — not a one-size-fits-all template. CHALLENGES THAT BUILD HABITS Built-in challenges — from a beginner-friendly 5-day start to a 72-hour deep fast — give you structure and milestones to work toward. Track progress, earn achievements, and build consistency. BIOMARKER TRACKING (OPTIONAL) For users who track glucose, ketones, GKI, or Dr. Boz Ratio: type readings in, or import them from your Keto-Mojo meter. See how your metabolic data trends alongside your fasting practice. Most users start without this — it's there when you're ready. ALSO INCLUDES - Intermittent and prolonged fasting schedules (16:8, 18:6, OMAD, 36h, 48h, 72h+) - Apple Health and Health Connect sync for weight, sleep and steps - Step history by week, month and year, with your own entries for the days you walked without your phone - Motivational notifications at key fasting milestones - Eating window and hydration tracking - Stool tracking for gut health awareness - Custom trackers for anything you want to monitor BUILT FROM EXPERIENCE SparkFast was born when co-founder Veronica — who changed her own health through fasting — realized she kept printing charts of estimated biological milestones and sticking them on her kitchen wall to stay motivated during 72-hour fasts. That piece of paper became this app. IMPORTANT The SPARK Chart shows estimated timelines based on published fasting research. Actual metabolic responses vary between individuals based on diet history, metabolic health, and other factors. SparkFast is a motivational and educational tool, not a medical device. YOUR PRIVACY SparkFast does not sell personal data. All information is stored securely and encrypted. SUBSCRIPTION SparkFast requires a subscription for full access. Options include monthly and yearly plans, both with a free trial. Payment is charged to your Apple ID at purchase and renews automatically unless cancelled at least 24 hours before the end of the current period. Manage subscriptions in App Store settings. Terms of Service: https://www.sparkfast.app/terms-of-service Privacy Policy: https://www.sparkfast.app/privacy-policy

StayFasted is the fasting app that actually keeps you going. Most fasts don't end because of the plan. They end in one hard half hour. StayFasted is built around that half hour: a timer you can trust, a guide to what to expect, and a check-in that answers back. A TIMER FOR EVERY FAST 16:8 · 18:6 · 20:4 · One Meal a Day · 36h · 48h · 72h. One button starts it. Forgot to start? Move the start time in seconds. Your fast also shows on your Lock Screen, in the Dynamic Island, in widgets and on Apple Watch. KNOW WHAT TO EXPECT, HOUR BY HOUR For each part of a fast: what is generally understood, what people often feel, and what tends to help. Timing differs from person to person. General information, not medical advice. CHECK IN WHEN IT GETS HARD Mood, hunger and energy in a few taps. With Pro, an AI replies to what you wrote, how you feel and why you started. It runs on your iPhone, and it never pushes you to carry on. BREATHE Short breathing sessions for the moment a craving arrives, and a guided deep rest for when you need to lie down for ten minutes. On your phone and on your wrist. FLUIDS AND ELECTROLYTES Log water, coffee and tea in one tap. See whether you are keeping an even pace through the day. Electrolyte reminders for longer fasts. END IT WELL Stop whenever you choose. A refeed guide walks you back to food gently, from liquids to normal meals. SEE YOUR PATTERNS Insights in plain words from your own data, always honest about how much data they are based on. Progress photos on a timeline. A monthly report you can share with your doctor or coach. APPLE WATCH See your fast, start or end it, log water, check in and breathe. APPLE HEALTH Optional. Reads weight, steps, sleep, resting heart rate and active energy. Saves weight, water and mindful minutes. You choose what to share. YOUR FASTING DATA STAYS ON YOUR PHONE No account and no sign-up. Your fasts, check-ins, photos and notes are stored on your iPhone. Three optional features use the internet, only if you turn them on: weather, scanning a drink's barcode, and Apple Music playlists. FREE - Timer for every fasting length - The hour-by-hour guide - Check-ins, fluid tracking and the refeed guide - Two breathing sessions - Apple Watch, widgets and Live Activities - Your last 10 fasts and 7 days of charts PRO - AI replies on every check-in - All breathing sessions and deep rest - Full analytics and a monthly report with PDF - Unlimited history, journal, measurements and supplements - Rhythm planner, drink scanner, photo comparison - Health Labs scanner for InBody, DEXA and blood panels - CSV export Pro: $5.99 a month or $39.99 a year. Lifetime: $49.99, one payment. StayFasted gives general information about fasting and is not medical advice. Talk to your doctor before you start fasting, especially if you are pregnant, under 18, have diabetes or an eating disorder, or take medication. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdevstandard/ Privacy Policy: https://stayfasted.app/privacy