FastWindow vs Aayu
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
FastWindow
Read full descriptionHide 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.
Aayu
Read full descriptionHide full description
Lose weight with intermittent fasting — and see when your body actually switches to fat burning. Most fasting apps show you a countdown. Aayu tracks six metabolic zones in real time, from the drop in glucose through fat burning, autophagy, and renewal. Fasting stops feeling like waiting and starts feeling like progress toward your goal weight. From the moment you begin a fast, Aayu tracks your body's journey through six metabolic zones in real time — from the early transition away from glucose, through the metabolic shift, into fat burning, autophagy, and renewal. At every stage, you'll see where you are, what your body is doing, and what comes next. Fasting stops feeling like waiting and starts feeling like progress. YOUR METABOLIC DISCIPLINE SCORE Aayu distils your fasting practice into a single score built from what genuinely matters: how long you fast, how consistently you show up, how well your fasts align with your natural overnight rhythm, how often you reach the deeper zones, and the momentum of your streak. PLANS THAT MEET YOU WHERE YOU ARE Start gently with 12:12 and progress to 14:10, 16:8, or 18:6 — free, forever, with no hidden limits. Aayu builds your starting plan around your profile, activity, and last-meal time, and includes safety guardrails: gentler plans are recommended for younger users and those at lower body weights. BREAK YOUR FAST PROPERLY How you end a fast matters as much as the fast itself. Aayu includes 30 curated break-fast meals — from steamed idli with coconut chutney to overnight oats and miso soup — each chosen for being gentle on a fasting gut, with an explanation of why it works and protein-forward options to help protect muscle. EVERYTHING ELSE YOU NEED, FREE - Real-time fasting timer with live zone tracking - Hydration tracking with one-tap quick-adds - Automatic step counting - Weight logging with trends - Personalised coaching cards for your first week and beyond - "Does it break my fast?" — a searchable reference for coffee, tea, sweeteners, supplements and more - A Learn library of clear, practical fasting articles - Smart reminders for fast start, milestones, and hydration - Cloud sync and full account deletion, anytime GO DEEPER WITH AAYU PRO When you're ready, Aayu Pro adds: - 30-day and all-time insight ranges - Smart Weight Projection based on your real fasting, weight, and activity data - Monthly PDF reports with score breakdown and next-month plan - Apple Health integration — see how fasting relates to your resting heart rate, HRV, sleep, and body composition - Advanced metrics including fat-burn estimates, deep autophagy hours, and gut rest - Advanced plans: 20:4, OMAD, 36-hour, 5:2, and 4:3 - Custom plans with weekday and weekend variation Pro is available as a monthly or annual auto-renewing subscription, managed through your App Store account. Cancel anytime. PRIVATE BY DESIGN Your health data is yours. Aayu runs on EU-based infrastructure, shows no ads, never sells your data, and lets you delete your account and data from within the app. A NOTE ON YOUR HEALTH Aayu provides general wellness information, not medical advice. Advanced metrics are estimates based on published research, not clinical measurements. Fasting isn't suitable for everyone — if you are pregnant, under 18, underweight, diabetic, or managing a medical condition, consult your doctor before fasting. Always take prescribed medication on schedule. Begin your first fast tonight — and for the first time, watch what your body does with it. Terms of Use : https://www.aayuwellness.app/terms Privacy Policy: https://www.aayuwellness.app/privacy
Screenshots
Verdict
The clearest difference is in-app purchases: Aayu at none against FastWindow's 1. On price, ads, device support and iOS requirement 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
Both are free to download. FastWindow sells 1 one-off in-app purchase. Aayu asks for nothing beyond the download.
| Parameter | FastWindow | Aayu |
|---|---|---|
| Price | Free | Free |
| Update frequency | — | Every 3 days |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 15.1 | 15.1 |
| Further details — not scored | ||
| Size | 37 MB | 54 MB |
| Age rating | 4+ | 17+ |
| Developer | PROJECTSNAPLABS LTD | Aayu Wellness Ltd |
In-app purchases
FastWindow
- FastWindow Pro$4.99
Aayu
No in-app purchases









