Comparison

Fastology vs Intermittent

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

Head to head
About

Fastology

This app provides structured tracking for intermittent fasting, going beyond simple timers. It helps users follow specific fasting schedules with clear phase progress, build consistency through streaks, and manage a flexible weekly plan. Focuses on discipline and reducing guesswork for a clearer fasting experience.

Highlights
  • Track various fast types (16:8, OMAD, extended)
  • Live phase-by-phase progress tracking
  • Build streaks from completed fasts
  • Flexible weekly fasting schedule
  • Review fasting history
  • Ask fasting questions with reviewed answers
  • Siri and Shortcuts integration
Features
Read full description

Fastology is a fasting tracker for people who want more than a timer. Fasting works when it is structured. Fastology helps you track 16:8, 18:6, OMAD, and extended fasts with clear phase progress, streaks that reflect completed fasts, and a weekly schedule that fits real life. Most fasting apps count hours. Fastology helps you follow through. WHY FASTOLOGY Structured, not reactive Follow a clear fasting rhythm instead of making it up as you go. See where you are Track each phase of the fast with live progress, so you always know where you stand and what comes next. Consistency over intensity Build streaks from completed fasts and focus on repeatability, not random extremes. Flexible weekly schedule Set your fasting rhythm for the week, then adjust specific days when life changes. Clear, focused experience No clutter. No noise. Just the tools that matter when you want to fast with more discipline and less guesswork. WHAT YOU CAN DO • Track 16:8, 18:6, OMAD, and extended fasts • Follow live phase-by-phase progress • Build streaks from completed fasts • Set a weekly schedule and adjust specific days • Review your fasting history over time • Ask fasting questions with reviewed answers and linked sources • Start a fast, check your phase, or search Fastology from Siri, Spotlight, Shortcuts, and Ask • On supported devices, use Apple Intelligence to explore your fasting history Fastology is built for people who want to fast with more clarity, more structure, and more follow-through.

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

Fastology4 screens
Intermittent4 screens

Verdict

The call

The clearest difference is rating: Intermittent at 5.0 against Fastology's 4.8. Intermittent also leads on ratings volume (32 vs 5) and iOS requirement (13.0 vs 17.0). On price, review sentiment, update cadence and ads 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Intermittent holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Intermittent has 32 ratings behind it against 5, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

Fastology ships an update fortnightly, Intermittent every 8 days. The most recent releases landed on September 9, 2026 and September 22, 2026 respectively.

Scorecard3 real differences · 7 level
Fastology versus Intermittent: the parameters behind the verdict, then further details
ParameterFastologyIntermittent
PriceFreeFree
Rating4.8 (5 ratings)5.0 (32 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings532 — better
Update frequencyFortnightlyEvery 8 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, Apple WatchiPhone, iPad, iPod — better
Requires iOS17.013.0 — better
Further details — not scored
Size40 MB39 MB
Age rating4+17+
DeveloperSmallScale Works LLCRohit Kumar

Customer experience

Fastology

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Intermittent

All ratings32 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews10 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Fastology

No in-app purchases

None

Intermittent

No in-app purchases

Questions

Is Fastology free?
Fastology is free to download, with no in-app purchases.
Is Intermittent free?
Intermittent is free to download, with no in-app purchases.
Which has better reviews, Fastology or Intermittent?
Intermittent is rated higher. Fastology averages 4.8 out of 5 from 5 ratings, while Intermittent averages 5.0 from 32 ratings.
Do Fastology or Intermittent have ads?
Neither Fastology nor Intermittent shows ads.
Which is updated more often, Fastology or Intermittent?
Fastology ships an update fortnightly, and Intermittent every 8 days. Most recently, Fastology was updated on September 9, 2026 and Intermittent on September 22, 2026.

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