fast_burn
Keiichiro Hayashida Health & Fitness iPhoneiPadiPod touch
fast_burn is a free Health & Fitness app for iPhone and iPad by Keiichiro Hayashida. Requires iOS 17.0. Updated June 1, 2026.
- Price
- Free
- on the App Store
- Size
- 1 MB
- Age 12+
- Updated
- Jun 1
- 2026 · v1.2
Screenshots
About fast_burn
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
What’s new
Version 1.2 · Updated June 1, 2026
"Auto-repeat fasting" is now off by default. You can turn it back on anytime from Settings.
App privacy
The developer, Keiichiro Hayashida, reported these privacy practices to Apple.
Data Not Collected
The developer does not collect any data from this app.
Alternatives to fast_burn
Looking for apps like fast_burn? Here are 6 similar apps on the App Store. The highest rated is AI Calorie Tracker: Scan Food (5.0/5), and all 6 are free to download.
-
FastBurn: Fasting Weight Loss
4.2
-
BeastInterval: Interval Timer
4.8
-
Zone Fitness Clubs
4.0
-
Titan - Workout Tracker & Log
4.7
-
AI Calorie Tracker: Scan Food
5.0
-
Andrra
5.0
| App | Rating | Price | Last updated | Compare |
|---|---|---|---|---|
| fast_burn | – | Free | June 1, 2026 | |
| FastBurn: Fasting Weight Loss | 4.3 / 5 (4) | Free | Jun 26, 2026 | Compare |
| BeastInterval: Interval Timer | 4.8 / 5 (4) | Free | May 16, 2026 | Compare |
| Zone Fitness Clubs | 4.0 / 5 (2) | Free | Sep 20, 2025 | Compare |
| Titan - Workout Tracker & Log | 4.7 / 5 (23) | Free | Oct 21, 2026 | Compare |
| AI Calorie Tracker: Scan Food | 5.0 / 5 (6) | Free | Oct 21, 2026 | Compare |
| Andrra | 5.0 / 5 (1) | Free | May 20, 2026 | Compare |
Compare fast_burn with the top alternatives: ratings, updates, ASO score and keyword gaps →