Comparison

Fasting Timer by TrainerDay vs JustFast

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

Head to head
About

Fasting Timer by TrainerDay

This app simplifies intermittent fasting with a one-tap start and customizable durations. Track your progress visually and review your fasting history. It's designed for easy habit building without complex features.

Highlights
  • One-tap fast start
  • Customizable fasting durations
  • Flexible start times
  • Visual progress tracking
  • Fasting history
  • Shareable results
Features
Read full description

Fasting Timer is a simple, no-fuss intermittent fasting tracker designed to help you build healthy fasting habits. It's the ultimate app for ADF fasters. Each day when you start your fast. It's just one click, even when you forget to start it at your normal fasting time. Features: • One-tap start - Begin your fast instantly • Customizable durations - Set your preferred fasting window (12, 14, 16, 18, 20+ hours) • Flexible start times - Start now or schedule for later • Visual progress - See your fasting progress at a glance • History tracking - Review your completed fasts • Share your achievements - Export and share your fasting results Whether you're doing 16:8, 18:6, or any other intermittent fasting schedule, this app makes it easy to track your fasting windows without complicated setup or unnecessary features. Free and simple. Start fasting today.

About

JustFast

This app offers a straightforward intermittent fasting timer. It focuses on tracking your fast with a clear, calm interface, providing insights into metabolic stages without gamification or pressure. It prioritizes privacy with on-device data storage and no accounts.

Highlights
  • One-tap start and stop
  • Live timer with accurate timekeeping
  • Metabolic milestone tracking
  • Plain-language explanations of milestones
  • Adjustable start/stop times
  • Ongoing notification for duration
  • Simple history of past fasts
  • 18 languages and dark design
Features
Read full description

Fasting is a beautifully simple intermittent-fasting timer that does one thing well: it tracks your fast. No goals to hit. No streaks to protect. No accounts, no ads, no clutter. Just tap once to begin, and a calm live timer counts your fast while a glowing ring fills toward the next stage your body moves through. WHY IT'S DIFFERENT Most fasting apps pile on dashboards, reminders, and pressure. This one strips fasting back to its essence — a clear timer you can glance at and put away. It's designed to feel quiet and focused, not gamified. WHAT YOU GET • One-tap start and stop, with a big, satisfying button • A live timer that keeps perfect time across restarts, time-zone changes, and daylight saving • Metabolic milestones — the ring fills toward the next stage (blood sugar settling, glycogen burning, fat burning, ketosis, autophagy, and more) • Tap any milestone for an honest, plain-language explanation of what's happening in your body • Forgot to start the timer? Just tap the ring to fix your start time. Forgot to stop? End your fast at the right time after the fact. • An ongoing notification shows your current duration at a glance • A simple history of past fasts — swipe to delete • 18 languages and a clean dark design HONEST BY DESIGN The milestone descriptions are written plainly and honestly. Where the science is still early or based mostly on animal research, we say so. This app is a timer and an educational companion — not medical advice. PRIVATE BY DEFAULT Your data stays on your device. There are no accounts, no sign-ups, no tracking, and nothing is uploaded. Fasting works for 16:8, OMAD, alternate-day, extended fasts, or any schedule you like — because it never forces a schedule on you. Note: Fasting is not a medical device and does not provide medical advice. Talk to a healthcare professional before starting any fasting regimen, especially if you are pregnant, nursing, taking medication, or have a medical condition.

Screenshots

Fasting Timer by TrainerDay4 screens
JustFast4 screens

Verdict

The call

The clearest difference is ratings volume: Fasting Timer by TrainerDay at 12 against JustFast's 1. Fasting Timer by TrainerDay also leads on iOS requirement (15.1 vs 18.0). On price, rating, ads and in-app purchases 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

On the App Store both sit at effectively the same score — 5.0 for Fasting Timer by TrainerDay against 5.0 for JustFast. That said, the two scores are not equally well evidenced: Fasting Timer by TrainerDay has 12 ratings behind it against 1, so its average is the more settled of the two.

Scorecard2 real differences · 8 level
Fasting Timer by TrainerDay versus JustFast: the parameters behind the verdict, then further details
ParameterFasting Timer by TrainerDayJustFast
PriceFreeFree
Rating5.0 (12 ratings)5.0 (1 ratings)
Positive reviews100.0% of reviews—
Number of ratings12 — better1
Update frequency—Fortnightly
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.1 — better18.0
Further details — not scored
Size30 MB20 MB
Age rating17+4+
DeveloperTrainerDay IncVitalii Vyrodov

Customer experience

Fasting Timer by TrainerDay

All ratings12 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

JustFast

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Fasting Timer by TrainerDay

No in-app purchases

None

JustFast

No in-app purchases

Questions

Is Fasting Timer by TrainerDay free?
Fasting Timer by TrainerDay is free to download, with no in-app purchases.
Is JustFast free?
JustFast is free to download, with no in-app purchases.
Which has better reviews, Fasting Timer by TrainerDay or JustFast?
Fasting Timer by TrainerDay and JustFast are both rated 5.0 out of 5 on the App Store, from 12 and 1 ratings respectively.
Do Fasting Timer by TrainerDay or JustFast have ads?
Neither Fasting Timer by TrainerDay nor JustFast shows ads.

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