SOL — Fasting Timer & Tracker
Danny Linsner Health & Fitness iPhoneiPadiPod touch
SOL — Fasting Timer & Tracker is a free Health & Fitness app for iPhone and iPad by Danny Linsner. Requires iOS 16. Updated October 15, 2026.
- Price
- Free
- on the App Store
- Size
- 7 MB
- Age 4+
- Updated
- Oct 15
- 2026 · v2.0.1
Screenshots
About SOL — Fasting Timer & Tracker
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.
What’s new
Version 2.0.1 · Updated October 15, 2026
• See how many people are fasting with you, right on your fast screen • Small improvements
App privacy
The developer, Danny Linsner, reported these privacy practices to Apple.
Data Not Linked to You
The following data, which may be collected but is not linked to your identity, may be used for the following purposes:
- Health & Fitness: Health, Fitness
Used for: App Functionality
Alternatives to SOL — Fasting Timer & Tracker
Looking for apps like SOL — Fasting Timer & Tracker? Here are 6 similar apps on the App Store. The highest rated is Intermittent Timer (5.0/5), and all 6 are free to download.
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Sundial: Fasting & OMAD Timer
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Intermittent - Fasting Timer
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Hone: Intermittent Fasting
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Intermittent Timer
5.0
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FastTrack Fasting Timer
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Stillhour: Fasting Timer
| App | Rating | Price | Last updated | Compare |
|---|---|---|---|---|
| SOL — Fasting Timer & Tracker | – | Free | October 15, 2026 | |
| Sundial: Fasting & OMAD Timer | – | Free | Jun 17, 2026 | Compare |
| Intermittent - Fasting Timer | – | Free | Apr 16, 2026 | Compare |
| Hone: Intermittent Fasting | – | Free | May 4, 2026 | Compare |
| Intermittent Timer | 5.0 / 5 (1) | Free | Jul 26, 2026 | Compare |
| FastTrack Fasting Timer | – | Free | Aug 3, 2026 | Compare |
| Stillhour: Fasting Timer | – | Free | May 18, 2026 | Compare |