PerfectFast vs Intermittent

PerfectFast helps you track intermittent and extended fasts with a calm, focused experience. Set up a fasting plan, follow your active fast, review your history, and see progress statistics without clutter. The app supports common fasting schedules, custom durations, reminders, fasting stages, history views, statistics, appearance settings, local data export, and Live Activity support on compatible devices. The Apple Watch companion lets you check your current or scheduled fast from your wrist, start or end a fast when your iPhone is nearby, and keep progress on your watch face with complications. Your fasting data stays on your device unless you choose to export or share it.

The intermittent fasting tracker that shows the biology happening inside you in real time: Fed, Lipolysis, Ketosis, Autophagy. Ad free fasting app. No account required. Most fasting apps give you a countdown clock and a streak to protect. Intermittent does something different. It shows you exactly which biological phase your body is in right now, and explains the science behind it with cited primary sources, not marketing copy. If you have ever wondered how to track fasting properly, or what is actually happening during a fast, this is the fasting tracker built for that question. WHY FASTING WORKS Intermittent fasting works because of what happens between meals, not just the absence of food. As your fast progresses, your body moves through distinct phases: burning through glucose reserves, shifting into fat burning lipolysis, entering ketosis, and eventually triggering autophagy, the cellular repair process linked to longevity and metabolic health. Understanding these transitions is what separates intentional fasting from guesswork. Intermittent maps every stage so your goals are grounded in biology, not motivation. KEY FEATURES PHASE AWARE FASTING TIMER A real time timer that tracks six biological phases: Fed, Early Fasting, Lipolysis, Ketosis, Autophagy, and Deep Fast. Each phase links to a free science article with primary sources cited. EVERY FASTING PROTOCOL, ONE APP Supports 12:12, 14:10, 16:8, 18:6, 20:4, OMAD (One Meal A Day), 36 hour, 48 hour, and 72 hour fasts. FREE FASTING SCIENCE LIBRARY A full library of fasting articles covering intermittent fasting, ketosis, autophagy, insulin response, and more. No subscription. No account. No paywall. SMART HYDRATION TARGET A science backed hydration goal that adapts to your weight, sex, age, and fasting duration. WEIGHT AND PROGRESS TRACKING Log your weight after each fast and track trends over time. Includes streak heatmap, phase reach history, and estimated fat vs glucose energy usage. PRIVATE CIRCLE AND END OF FAST REFLECTION Share your fast with a small private group. Applause only responses. No comparison. No gamification. HOME SCREEN WIDGET AND CROSS DEVICE SYNC Keep your fasting timer visible with a home screen widget. Your data syncs across devices privately without third party trackers. WHO IT IS FOR Intermittent is built for adults who want to understand fasting, not be coached through it. If you follow research on metabolic health, read about longevity, or want a fasting routine grounded in biology rather than points or streaks, this app is for you. Suitable for both beginners and experienced fasters. HOW IT WORKS Choose your fasting protocol, from 12:12 to extended fasts Start your timer and track your biological phase in real time Tap any phase to read the science and log your reflection at the end No account required to start. No subscription required to access the library.