Supported Features
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VoiceOver
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Voice Control
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Larger Text
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Dark Interface
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Differentiate Without Color Alone
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Sufficient Contrast
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Reduced Motion
Furolog
Onsen & Sauna Tracker
Free · In‑App Purchases
Turn every soak into a story you can learn from.
Furolog is a bathing journal for onsen, sento, sauna and cold-plunge fans. With a compatible Apple Watch, it detects when you enter the water and records temperature and heart rate, building a timeline of every soak, rest, sauna and cold plunge. Prefer to stay in control? Record manually from Apple Watch or iPhone.
Sensor-based water temperature tracking is available on Apple Watch Series 10 or later and Apple Watch Ultra models.
TRACK AS YOU BATHE
• Automatic water detection on compatible Apple Watch models
• Water temperature changes recorded as often as every 5 seconds
• Continuous heart rate monitoring with configurable alerts
• Manual dip, sauna and temperature controls on Apple Watch and iPhone
• A clear activity timeline for every soak, rest, sauna and cold plunge
• Tag sessions with 13 onsen water types and 12 sauna types
REMEMBER EVERY VISIT
• Add ratings, notes and photos to your sessions
• Save favorite sessions and facilities
• See your complete visit history for each location
• Keep your journal in sync across devices with iCloud
DISCOVER YOUR NEXT STOP
• Find nearby onsen, sento and sauna on an interactive map
• Track the prefectures you have visited and aim for all 47
• See community water temperatures and visit totals when available
UNDERSTAND YOUR PATTERNS — FUROLOG PRO
• Explore temperature, duration and frequency trends
• Review heart rate zones, HR response and post-session recovery
• Follow heat tolerance, cold tolerance and hot-cold contrast
• See your sauna heart rate climb and recovery pattern
• Find Your Perfect Session from the routines you rate highest
MAKE IT YOURS
• Create share cards in three layouts with customizable gradient backgrounds
• Add photo backgrounds and choose from 9 alternate app icons with Furolog Pro
• Choose from 7 themes
• Use Furolog in English or Japanese
All recording features on Apple Watch and iPhone are free. Furolog Pro unlocks advanced analytics and additional customization.
PRIVACY AND PERMISSIONS
Community sharing is optional and can be disabled globally or for individual sessions. Shared records are anonymized and used to provide facility water temperatures and visit totals. Notes, photos, heart rate data, exact timestamps, home addresses and precise locations are never shared.
HealthKit access is required to record heart rate. Location access is used for session mapping and nearby facility discovery. Heart rate alerts are informational and are not medical guidance.
IMPORTANT
Use of Apple Watch in hot water is at your own risk. Apple does not recommend submerging Apple Watch in hot springs or using it in saunas. We are not responsible for damage to your device.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://www.nimikko.co.jp/en/furolog-privacy-policy
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Bug fixes and improvements
The developer, Nimikko K.K., 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 Linked to You
The following data may be collected but it is not linked to your identity:
- Health & Fitness
- Location
The developer indicated that this app supports the following accessibility features. Learn More
Information
- Seller
- NIMIKKO K.K.
- Size
- 101.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 26.2 or later.
- iPhone
Requires iOS 26.2 or later. - Apple Watch
Requires watchOS 26.2 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Furolog Pro Lifetime $19.99
- Furolog Pro $2.99
- Copyright
- © 2026 Nimikko K.K.