Luminous Future Technology
FatBurn Watch
FatBurn Watch

FatBurn Watch

Heart rate alerts that keep you in the fat-burning zone on Apple Watch

Apple Watch watchOS 10+ iPhone iOS 17+
Privacy Policy
What data this app handles
Terms of Use
Conditions for using the app
About

Overview

Apple Watch monitors your target zone (60-70% of HRmax) in real time. Haptic, sound and on-screen alerts when you exceed it; sessions saved to HealthKit.

Latest Versions

Latest version

  • iPhone 1.5 (Build 97) Released: 2026-06-19 ・ Min OS: iOS 17+
  • Watch 1.5 (Build 97) Released: 2026-06-19 ・ Min OS: watchOS 10+

App-side updated: 2026-06-22

What's New

Release notes

- Added a Workout History & estimated fat-burn tab on iPhone (weekly / monthly / cumulative + charts)
- Unified the Direct bpm mode in zone settings with sliders
- Direct bpm default values now derive from your estimated HRmax
- Streamlined the profile screen to focus on choosing the HRmax formula (Fox / Tanaka)
Screenshots

FatBurn Watch

Fat-burning zone tracking on Apple Watch
Fat-burning zone tracking on Apple Watch
Heart-rate zone and fat-burning score in real time
Heart-rate zone and fat-burning score in real time
Haptic alert when you exceed the zone
Haptic alert when you exceed the zone
Personalize via your HRmax profile
Personalize via your HRmax profile
Support

Support / FAQ

Check here first for help with the app.

    1. Open the app on iPhone and enter age, sex, weight and HRmax
    2. Set your target zone (fat-burning zone) and alert sensitivity
    3. Launch the app on Apple Watch and tap Start
    4. Heart rate shows in real time; you get haptic, sound and on-screen alerts when you exceed the threshold
    5. Tap Stop to save the workout to HealthKit

  • To read heart rate in real time, judge the fat-burning zone, and save workouts. You can change permission any time from Health → Sources, or Settings → Privacy & Security → Health.

  • Common estimates:

    • Simple: 220 − age
    • Tanaka formula (often more accurate): 208 − 0.7 × age

    Use a measured value if you have one. The app's numbers are guidance, not medical advice.

    • Is Apple Watch fitted snugly on your wrist?
    • Are notifications allowed for the app in Settings?
    • Is Focus / Do Not Disturb active?
    • Does your sensitivity (threshold + duration) match your effort?
    • iPhone: iOS 17+
    • Apple Watch: watchOS 10+
    • iPhone & Apple Watch must be paired

  • This app is not a medical device. Do not use for diagnosis, treatment or prevention. Consult a doctor before exercise if you have cardiac concerns.

  • If the answers above don't resolve your issue:

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