Comparison

FastWindow vs Intermittent

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

FastWindow

Features
Read full description

FastWindow does one thing. It shows you how long you've been fasting and when you can eat. Every major fasting app has become a wellness platform — coaching subscriptions, quizzes, recipe feeds, and paywall friction. FastWindow strips all of that away. ONE-TAP FASTING TIMER Open the app. Tap start. Done. No quiz about your goals. No onboarding survey. No account creation. Just a clean fasting timer that works. You see two things: • How long you've been fasting (elapsed time) • When you can eat (remaining time) That's it. That's the app. FASTING PRESETS BUILT IN Choose your fasting window in one tap: • 16:8 (16 hours fasting, 8 hours eating) • 18:6 (18 hours fasting, 6 hours eating) • 20:4 (20 hours fasting, 4 hours eating) • OMAD (One Meal A Day) • Custom durations (Pro feature) No coaching. No meal plans. No calorie tracking. Just fasting. FEATURES THAT MATTER • One-tap fasting timer • Live elapsed and remaining time • Fasting presets (16:8, 18:6, 20:4, OMAD) • 7-day fast history at a glance • Calendar heatmap to see patterns • Backdate your start time if you forget to start the timer • Local notifications when your fast ends • No account required. Ever. • No subscription. Ever. FASTWINDOW PRO — One Time Purchase Upgrade once to unlock: • Unlimited fast history (beyond 7 days) • Custom fasting durations (set any hours:minutes) • Weight log with trend visualization • Apple Health export (weight, fasting data) • Advanced stats (average fast length, streak tracking) Pay once. £4.99. Yours forever. No renewal, no monthly fee, no subscription. WHY FASTWINDOW EXISTS The fasting app category has a problem. Every major app pushes you toward: • Subscription upsells (coaching, premium insights, meal plans) • Onboarding quizzes (goals, weight, activity level, dietary preferences) • Wellness bloat (recipes, articles, community challenges, step tracking) FastWindow rejects all of that. If you need a fasting coach, use Zero. If you want recipes and meal plans, use Fastic. If you want community challenges, use BodyFast. But if you just want to know how long you've been fasting — and that's it — FastWindow is for you. PERFECT FOR • People practicing intermittent fasting (16:8, 18:6, OMAD, etc.) • Users frustrated by fasting app subscriptions • Anyone who wants a timer, not a wellness platform • People who value simplicity over features • Users tired of onboarding quizzes and paywalls WHO FASTWINDOW IS NOT FOR FastWindow does not provide: • Coaching or fasting advice • Meal plans or recipes • Calorie tracking or macros • Community features or challenges • Water intake or step tracking • Body measurements beyond weight If you need those features, consider Zero, Fastic, or BodyFast. FastWindow is intentionally minimal. PRIVACY & SIMPLICITY • No account creation required • No email, no password, no profile • All data stored locally on your device • No cloud sync (intentional — keeps it simple) • No third-party analytics or tracking • Offline-first design NO SUBSCRIPTION MEANS NO SUBSCRIPTION Other fasting apps say "free" but push monthly subscriptions for basic features like custom fasting durations or history beyond 7 days. FastWindow is different: one optional upgrade, one price, lifetime access. No coaching upsells, no premium tiers, no renewal fatigue. Free version: 7-day history, preset durations (16:8, 18:6, 20:4, OMAD), basic timer Pro version: £2.99 once, everything unlocked, forever MEDICAL DISCLAIMER FastWindow is not medical advice. Consult a healthcare professional before beginning any fasting program, especially if you have a medical condition or take medications. SUPPORT & CONTACT Questions? Feedback? Contact us at karl@projectsnaplabs.com FastWindow is independently developed with your focus and simplicity as the top priorities. Download FastWindow today and track your fasts without the bloat, subscriptions, or friction.

About

Intermittent

This app tracks your fasting progress by showing real-time biological phases like ketosis and autophagy. It provides science-backed explanations for each stage and supports various fasting protocols without requiring an account or subscription.

Highlights
  • Real-time biological phase tracking (Fed, Lipolysis, Ketosis, Autophagy)
  • Support for multiple fasting protocols (12:12 to 72-hour fasts)
  • Free science library with cited primary sources
  • Adaptive hydration target
  • Weight and progress tracking with trend analysis
  • Private sharing circle with applause-only responses
  • Home screen widget and cross-device sync
Features
Read full description

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.

Screenshots

FastWindow4 screens
Intermittent4 screens

Verdict

The call

The clearest difference is in-app purchases: Intermittent at none against FastWindow's 1. Intermittent also leads on iOS requirement (13.0 vs 15.1). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. FastWindow sells 1 one-off in-app purchase. Intermittent asks for nothing beyond the download.

Scorecard2 real differences · 8 level
FastWindow versus Intermittent: the parameters behind the verdict, then further details
ParameterFastWindowIntermittent
PriceFreeFree
Rating—5.0 (46 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—46 — better
Update frequency—Every 10 days
AdsNoNo
In-app purchasesYesNo — better
Monetization—Free
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.113.0 — better
Further details — not scored
Size37 MB39 MB
Age rating4+17+
DeveloperPROJECTSNAPLABS LTDRohit Kumar

In-app purchases

1 purchases

FastWindow

One-time1
  • FastWindow Pro$4.99
None

Intermittent

No in-app purchases

Questions

Is FastWindow free?
FastWindow is free to download, with in-app purchases available.
Is Intermittent free?
Intermittent is free to download, with no in-app purchases.
Do FastWindow or Intermittent have ads?
Neither FastWindow nor Intermittent shows ads.

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