fast_burn
Intermittent Fasting Timer
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Fasting made simple. FastBurn shows what's happening in your body as you fast - from fat burning to autophagy - so every hour feels like
progress.
FASTING TIMER
One tap to start. A ring UI tracks your elapsed time and body phase: blood sugar rising, fat burning, ketosis, autophagy.
PLANS THAT FIT YOU
Your goal, body type, and experience determine the best protocol:
- 16:8 (16h fast / 8h eat)
- 18:6 (18h fast / 6h eat)
- 20:4 (20h fast / 4h eat)
- 36-hour extended fast
WEIGHT TRACKING + APPLE HEALTH
Log weight and view trends. Syncs automatically with Apple Health.
STATS & CALENDAR
Total fasts, average duration, best streak - all at a glance. Calendar view shows your daily history.
SMART REMINDERS
Customize alerts for fast start, phase changes, and eating windows.
FREE FEATURES
- 16:8 fasting timer
- Fasting history & basic stats
- Weight log
PRO FEATURES
- All fasting plans (18:6, 20:4, 36h)
- Detailed body phase tracking
- Full statistics & trend charts
- Fasting calendar
- Unlimited fasting history
SUBSCRIPTION DETAILS
FastBurn Pro is an auto-renewable subscription.
- Annual plan: includes a 7-day free trial
- Monthly plan
- Payment is charged to your Apple ID at confirmation
- Subscription auto-renews unless canceled at least 24 hours before the current period ends
- Unused portion of a free trial is forfeited upon purchase
- Manage or cancel: Settings > Apple ID > Subscriptions
Terms of Use: https://fastburn-legal.vercel.app/terms.html
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
"Auto-repeat fasting" is now off by default.
You can turn it back on anytime from Settings.
The developer, Keiichiro Hayashida, 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 Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Keiichiro Hayashida
- Size
- 1.2 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
13+
- 13+
- Infrequent
Medical Treatment information
Contains
Health or Wellness Topics
- In-App Purchases
Yes
- FastBurn Pro (Monthly) $4.99
- FastBurn Pro (Annual) $29.99
- Copyright
- © 2026 FastBurn