FastOn
See your fasting from inside
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
A fasting timer that shows what's happening inside — fat burning, ketosis, autophagy in real time. Widget & Live Activity. Fully offline, no sign-up.
A fasting timer that lets you see what's happening inside your body — even without opening the app.
FastOn helps you keep a 16-hour intermittent fast with a clean, focused timer. It works fully offline, needs no account, and keeps all your data on your device.
VISUALIZE YOUR FAST
As time passes, FastOn shows what's happening inside your body in real time:
Digesting → Blood sugar → Fat burning → Ketosis → Autophagy → Growth hormone → Deep repair
It's not just a countdown — knowing "fat burning starts soon" is what keeps you going.
Tap any stage to learn the science behind it and what benefits to expect.
FREE FEATURES
- Start/stop a fast in one tap (backdate from your last meal)
- Circular timer + real-time body stage
- 16:8 plan
- Streak tracking
- Last 7 days of history
- Water intake tracker
- Mood & energy self-logging
- Confetti celebration + SNS share card on completion
PREMIUM
- All plans (18:6 / 20:4 / OMAD / 5:2 / Custom)
- Home screen Widget + Live Activity (remaining time & stage on Lock Screen and Dynamic Island)
- Full statistics + insights
- AI Advice (personalized tips based on your fasting patterns)
- Weight tracking + goal weight line + HealthKit
- 20 badges / achievements with categories
- CSV data export
- Eating window end & streak crisis notifications
- No ads
NOTE
This app does not provide medical advice. Body-stage information is a general guideline based on common scientific knowledge and varies by individual. If you have a medical condition or are pregnant, please consult your doctor.
SUBSCRIPTION
- Monthly ¥480 / Yearly ¥2,900 (yearly includes a 7-day free trial)
- Payment is charged to your Apple ID at confirmation.
- It renews automatically unless auto-renew is turned off at least 24 hours before the end of the period.
- Manage or cancel in Settings > Apple ID > Subscriptions.
Terms of Use and Privacy Policy are available in the app settings and from the store links.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
v1.1 Update
- Water tracker — log your hydration on the home screen
- Mood & energy log — track how you feel during fasts
- AI Advice — personalized tips based on your fasting data (Premium)
- 20 badges — organized by category with progress tracking
- Stage details — tap any body stage for science-based info
- Goal weight — see your target line on the weight chart
- Share cards — share your fasting milestones on social media
- CSV export — download your fasting and weight history
- Plus improved notifications, settings, and more
The developer, Masahiro Akebi, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Identifiers
Data Linked to You
The following data may be collected and linked to your identity:
- Location
- Identifiers
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Masahiro Akebi
- Size
- 31.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
9+
- 9+
- Contains
Advertising
Health or Wellness Topics
- In-App Purchases
Yes
- Premium (Lifetime) $22.99
- Premium (Yearly) $17.99
- Premium (Monthly) $2.99
- Copyright
- © 2026 naname0109