SOL — Fasting Timer & Tracker
Know what's happening inside
Only for iPhone
Free · In-App Purchases
iPhone
SOL shows what is happening in your body at every stage of your fast, backed by real science.
SOL (솔) is Korean for pine tree. Like the pine that endures through every season, SOL stands with you through every fast.
WHAT MAKES SOL DIFFERENT
Most fasting apps just show a timer. SOL shows you what is happening inside your body as the hours pass, with the research behind it.
As you fast, SOL guides you through eight phases:
Fed State, Insulin Dropping, Fat Burning, Ketosis, Autophagy, Deep Autophagy, Growth Hormone Surge and Immune Reset.
FEATURES
• A calm timer with a progress ring and phase markers
• Your fast on the lock screen and in the Dynamic Island
• All 8 phases explained, with links to the published studies
• A goal dial from 12 to 72 hours, or an open fast with no limit
• Started earlier? Set the time you last ate, and correct it later
• Switch the timer between time elapsed and time to go
• A daily reminder to start your fast
• Your Journey: stats, streaks, a 7 day view and your history
• Edit, add or delete past fasts
• Guidance on breaking your fast gently
• Home screen widget
• "Start my fast" with Siri
• Share your results with a beautiful card
• Light and dark mode with handcrafted watercolor textures
FASTING TOGETHER
If you like, join the live count of people fasting right now. It is optional, anonymous and off until you turn it on.
YOUR DATA
No account, no ads, no tracking. Your fasting data stays on your device unless you choose to join the community count or turn on iCloud backup.
DESIGNED WITH INTENTION
SOL is inspired by the simplicity of nature. No clutter and no paywall. Just you, your fast, and a clearer picture of what your body is doing. SOL is free. If you enjoy it, you can leave a tip.
ABOUT THE SCIENCE
Phase information is based on peer-reviewed research, with direct links to the sources. Some findings come from animal studies, and every body responds differently. SOL offers general wellness information and is not medical advice. Please talk to a doctor before fasting, especially for longer fasts.
Begin your fast. Know your body. Grow like the pine.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
SOL 2.0 is the biggest update yet.
• A new goal dial, with 12h and 14h goals for beginners
• Your fast on the lock screen and in the Dynamic Island
• Edit, add or delete fasts in Your Journey, with a 7 day view
• Correct your start time, and switch the timer to a countdown
• A daily reminder to start your fast
• Settings are now one tap away, on the home screen
• Guidance on breaking your fast, and the science readable any time
• Optional: join the live count of people fasting right now
• Optional: back up your history to your own iCloud
• "Start my fast" with Siri
• A tip jar, if you would like to support SOL
Plus many small fixes and a calmer design.
The developer, Danny Linsner, 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
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- Danny Linsner
- Size
- 7.1 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 16 or later.
- iPhone
Requires iOS 16 or later. - iPod touch
Requires iOS 16 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Pine Tip USD 8.99
- Sapling Tip USD 3.99
- Seedling Tip USD 1.99
- Copyright
- © Danny Linsner