SparkFast - Fasting Tracker

SparkFast App

In-app purchases

About this app

Most fasting apps count hours. SparkFast shows you what those hours might mean — estimated biological milestones that give you a reason to keep going.

Whether your goal is weight loss, fat burning, metabolic health, or more energy, SparkFast combines science-based motivation with guided refeeding and AI-powered personalization.

🔬 THE SPARK CHART

The SPARK Chart visualizes five estimated biological processes during your fast — from insulin changes to fat burning, ketone production, and deep cellular recycling — based on published research.

Instead of staring at a blank timer, see a roadmap of what you're workin toward. It's the difference between "I've fasted 36 hours" and "I'm in the estimated deep autophagy zone."

The SPARK Chart shows estimated timelines. Actual responses vary based on diet history and metabolic health. It's a motivational roadmap, not a diagnosis.

🍽️ 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 (36h, 48h, 72h, 96h) and dietary preference. No more Googling "how to break a 72-hour fast" mid-fast.

🤖 AI-POWERED FASTING PLANS

Tell SparkFast 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 fasting challenges give you structure:
• Fast Start 5 — beginner-friendly 5-day introduction
• Spark21 — 21-day intermittent fasting habit
• Metabolic Reset — deeper prolonged fasting
• 72-Hour Challenge — the ultimate deep fast
• Sardine Fast — guided introduction to prolonged fasting

⚖️ WEIGHT LOSS & METABOLIC HEALTH

SparkFast makes intermittent fasting easier to maintain:
• Flexible fasting tracker and schedules
• Intermittent fasting timer with smart reminders
• Weight and body measurement tracking
• Visual progress charts
• Eating window tracking

📊 GLUCOSE, KETONES & METABOLIC TRACKING (OPTIONAL)

Log glucose, ketones, GKI, and Dr. Boz Ratio. Sync from Keto-Mojo, Google Fit, or enter manually. Most users start without this — it's there when you're ready.

💡 ALL FASTING PROTOCOLS

• 12:12, 14:10, 16:8, 18:6
• OMAD (One Meal a Day)
• 36h, 48h, 72h+ prolonged fasting
• Custom fasting schedules

🌱 BUILT FROM EXPERIENCE

SparkFast was born when co-founder Veronica — who went from BMI 32 to normal BMI through keto and fasting — kept printing charts of estimated biological milestones on her kitchen wall to stay motivated during 72-hour fasts. That piece of paper became this app.

✨ WHY SPARKFAST?

✔ SPARK Chart with estimated biological milestones
✔ Guided refeeding protocols for prolonged fasts
✔ AI-powered personalized fasting plans
✔ Built-in challenges for habit building
✔ Intermittent and prolonged fasting support
✔ Glucose, ketone, and metabolic tracking
✔ Google Fit and Keto-Mojo integration
✔ Motivational notifications at key milestones
✔ Custom trackers and stool tracking

Start your fasting journey with SparkFast — the fasting tracker that shows you why every hour counts.

Subscription required for full access. Monthly and yearly plans available, both with free trial.

Privacy: https://www.sparkfast.app/privacy-policy
Terms: https://www.sparkfast.app/terms-of-service

What’s new

- Fixed incorrect subscription prices displayed in the app. Now shows the correct $6.99/month and $64.99/year pricing.