Comparison

FastTrack Fasting Timer vs SOL

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

FastTrack Fasting Timer

Features
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FastTrack is the cleanest, most intentional way to track your intermittent fast. No clutter. No noise. Just a precise countdown that keeps you focused — glanceable from your Dynamic Island and Lock Screen without ever opening the app. Live Activities put your progress exactly where you need it. FastTrack uses iOS Live Activities to display a real-time countdown on the Dynamic Island and Lock Screen. Your fast is always visible, always accurate — even when your phone is sitting face-down on a desk. Every protocol, handled. Whether you fast 16:8, 18:6, 20:4, or push through an extended 36 or 72-hour window, FastTrack supports them all — plus fully custom durations. Set it once and let the app do the rest. Your history, beautifully organized. A calendar view gives you a complete record of every fast at a glance. Tap any day to see the full breakdown. Weekly charts, monthly trends, personal bests, and consistency tracking reveal what's actually working. Available with Pro. Streaks that hold you accountable. FastTrack tracks your fasting streak, sends a heads-up when it's at risk, and celebrates every milestone you hit. Consistency compounds — this is how you measure it. Synced with Apple Health. Fasting windows are recorded automatically, so your data lives where your other health metrics do. Smart notifications remind you when to start, alert you as the finish line approaches, and confirm every completed fast. No ads. No tracking. No fluff. FastTrack does exactly what it says and nothing it shouldn't. All your data is yours — export everything to CSV anytime. Pro unlocks advanced insights, trends, and export tools for people who want the full picture. Start your fast. FastTrack handles the rest. Terms of Use: https://fasttrackfasting.app/terms Privacy Policy: https://fasttrackfasting.app/privacy

About

SOL

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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.

Screenshots

FastTrack Fasting Timer4 screens
SOL4 screens

Verdict

The call

The clearest difference is iOS requirement: SOL at 16 against FastTrack Fasting Timer's 18.0. On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price Ā· Rating Ā· Positive reviews Ā· Number of ratings Ā· Update frequency Ā· Ads Ā· In-app purchases Ā· Monetization Ā· Best chart rank Ā· Devices Ā· Requires iOS

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

Both are free to download. FastTrack Fasting Timer sells 2 in-app purchases, starting at $1.99 per month and SOL sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Scorecard1 real difference Ā· 5 level
FastTrack Fasting Timer versus SOL: the parameters behind the verdict, then further details
ParameterFastTrack Fasting TimerSOL
PriceFreeFree
Update frequency—Fortnightly
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPadiPhone, iPod
Requires iOS18.016 — better
Further details — not scored
Size2 MB7 MB
Age rating4+4+
DeveloperChris KarlinDanny Linsner

In-app purchases

2 purchases

FastTrack Fasting Timer

Subscriptions2
  • Pro Monthly$1.991 Month
  • Pro Yearly$14.991 Year
3 purchases

SOL

One-time3
  • Seedling Tip$1.99
  • Sapling Tip$3.99
  • Pine Tip$8.99

Questions

Is FastTrack Fasting Timer free?
FastTrack Fasting Timer is free to download, with in-app purchases available.
Is SOL free?
SOL is free to download, with in-app purchases available.
Do FastTrack Fasting Timer or SOL have ads?
Neither FastTrack Fasting Timer nor SOL shows ads.

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