Comparison

FastFlow vs 天使と悪魔のファスティング

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

Head to head
About

FastFlow

This app helps users manage intermittent fasting schedules with a visual timer and customizable patterns. It also allows for weight tracking, meal logging with photos, and smart notifications to build healthy habits.

Highlights
  • Circular fasting timer
  • Flexible fasting patterns
  • Weight progress graph
  • Meal logging with photos
  • Smart notifications
  • Cloud data sync
Features
Read full description

【Who Is This For?】 • Starting 16:8 intermittent fasting • Want easy fasting time management • Track and visualize weight changes • Achieve autophagy benefits for healthy weight loss 【Key Features】 ■ Beautiful Circular Timer Intuitive display showing remaining fasting or eating time. Elegant design with clear progress visualization. ■ Flexible Fasting Patterns • 16:8 (16-hour fast / 8-hour eating window) • 18:6 (18-hour fast / 6-hour eating window) • 14:10 (14-hour fast / 10-hour eating window) • Custom schedules ■ Weight Progress Graph Record daily weight and visualize changes with line graphs. See your fasting results clearly. ■ Meal Log Document meals with photos. Review what you've eaten anytime. ■ Smart Notifications Get push notifications for fasting start and end times. Build lasting habits effortlessly. ■ Cloud Sync Securely backup your data to the cloud. Transfer seamlessly when switching devices. 【Benefits of Intermittent Fasting】 • Activate autophagy for cellular renewal • Improve insulin sensitivity • Enhance fat burning • Boost focus and mental clarity 【Why FastFlow?】 • 100% free with all features unlocked • Simple, intuitive interface • Privacy-focused design • Clean, distraction-free experience Download now and start your healthy fasting journey!

About

天使と悪魔のファスティング

Features
Read full description

Fast at your pace on a quiet island. Fasting Island is an intermittent fasting timer with two very different companions on your shoulders. The angel cheers you on, the devil tempts you to stop, and sometimes they both break character. Their playful banter keeps fasting from feeling too serious. SIMPLE FASTING TIMER Choose a 12:12, 14:10, or 16:8 plan. Start and finish with a tap, check elapsed time and goal progress, and adjust the start time later if needed. SIX FASTING STAGES Follow an easy-to-read guide through six estimated stages, from digestion and steadier blood sugar to fat use, ketosis, and autophagy-related repair. Stage timing is educational and may vary from person to person; it is not a medical measurement. ANGEL & DEVIL COMPANIONS Get encouragement from one shoulder and comic temptation from the other. Choose male or female character versions and enjoy occasional role reversals. HISTORY & STATISTICS Keep your fasting history without a time limit. Review recent sessions, totals, longest and average fasts, view a weekly chart, and export your records as CSV. OFFLINE AND PRIVATE The timer and on-device records work without an internet connection. No account is required, and your records stay on your device. SAFETY Fasting Island supports healthy routines but does not provide medical advice. Stop if you feel unwell. It is not recommended during pregnancy or for people with a history of eating disorders. If you have a medical condition or take medication, consult a qualified healthcare professional before fasting.

Screenshots

FastFlow4 screens
天使と悪魔のファスティング4 screens

Verdict

The call

The clearest difference is update cadence: 天使と悪魔のファスティング at every 10 days against FastFlow's every 4 months. FastFlow's advantage is iOS requirement (15.1 vs 18.0). On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

FastFlow ships an update every 4 months, 天使と悪魔のファスティング every 10 days. The most recent releases landed on September 16, 2026 and September 13, 2026 respectively.

Scorecard2 real differences · 6 level
FastFlow versus 天使と悪魔のファスティング: the parameters behind the verdict, then further details
ParameterFastFlow天使と悪魔のファスティング
PriceFreeFree
Positive reviews100.0% of reviews—
Update frequencyEvery 4 monthsEvery 10 days — better
AdsYesYes
In-app purchasesNoNo
MonetizationAd-supported—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.1 — better18.0
Further details — not scored
Size34 MB51 MB
Age rating12+17+
DeveloperCaprio LabRYOJI TAKAHASHI

In-app purchases

None

FastFlow

No in-app purchases

None

天使と悪魔のファスティング

No in-app purchases

Questions

Is FastFlow free?
FastFlow is free to download, with no in-app purchases.
Is 天使と悪魔のファスティング free?
天使と悪魔のファスティング is free to download, with no in-app purchases.
Do FastFlow or 天使と悪魔のファスティング have ads?
Both FastFlow and 天使と悪魔のファスティング show ads.
Which is updated more often, FastFlow or 天使と悪魔のファスティング?
FastFlow ships an update every 4 months, and 天使と悪魔のファスティング every 10 days. Most recently, FastFlow was updated on September 16, 2026 and 天使と悪魔のファスティング on September 13, 2026.

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