Comparison

SOL vs Vow Fasting

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

Head to head
About

SOL

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SOL (솔) — 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's actually happening inside your body — in real time. As you fast, SOL guides you through each biological phase: Fed State → Insulin Dropping → Fat Burning → Ketosis → Autophagy → Deep Autophagy → Growth Hormone Surge → Immune Reset FEATURES • Beautiful minimal timer with progress ring • Real-time body phase updates with scientific sources • Full body timeline — see all 8 phases and your progress • Tap any phase for in-depth science and PubMed sources • Smart notifications at each milestone • Stats dashboard — track your fasting journey • Background timer — keeps running when you close the app • Light & dark mode with handcrafted watercolor textures • Home screen widget • Community pulse — you're not fasting alone • Share your results with a beautiful card FASTING GOALS Choose from 16h, 18h, 20h, 24h, 36h, 48h, 72h, or go Open with no time limit. Hit your goal? Extend to the next level. DESIGNED WITH INTENTION SOL is inspired by the simplicity of nature. No clutter, no ads, no unnecessary features. Just you, your fast, and the knowledge of what your body is doing. All body phase information is based on peer-reviewed scientific research with direct links to PubMed sources. Begin your fast. Know your body. Grow like the pine.

About

Vow Fasting

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Vow is a refined intermittent fasting tracker built for calm daily discipline. Start a fast, follow your progress, and understand each stage as your body moves through metabolic phases like digesting, fat burning, ketosis, and autophagy. Vow keeps fasting focused with a precise timer, clear progress, thoughtful reminders, and a minimal dark design made for daily practice. Whether you follow 16:8, 18:6, 20:4, 24-hour fasts, or custom fasting goals, Vow helps you track every session with clarity. FEATURES • Elegant fasting timer with real-time progress • Intermittent fasting plans including 16:8, 18:6, 20:4, and 24h • Metabolic phase tracking from digesting to fat burning, ketosis, and autophagy • Fasting history, streaks, and weekly insights • Custom and extended fasting durations • Goal reminders and phase update notifications • Minimal dark interface with premium themes • Home Screen widgets and Live Activity support Vow Pro Unlock extended fasting protocols, custom durations, premium themes, advanced insights, and premium widgets. Vow is not medical advice. If you have a medical condition, are pregnant, under 18, or have a history of eating disorders, consult a healthcare professional before fasting. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://vowfasting.com/privacy

Screenshots

SOL4 screens
Vow Fasting4 screens

Verdict

The call

The clearest difference is in-app purchases: SOL at none against Vow Fasting's 2. On price, update cadence, ads 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. Vow Fasting sells 2 in-app purchases, starting at $4.99 per month. SOL asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly fortnightly. Both last shipped on October 6, 2026.

Scorecard1 real difference Ā· 5 level
SOL versus Vow Fasting: the parameters behind the verdict, then further details
ParameterSOLVow Fasting
PriceFreeFree
Update frequencyFortnightlyFortnightly
AdsNoNo
In-app purchasesNo — betterYes
DevicesiPhone, iPod — betteriPhone
Requires iOS16 — better17.6
Further details — not scored
Size6 MB13 MB
Age rating4+4+
DeveloperDanny LinsnerFILIP LUCCA KEJSER DAMICI

In-app purchases

None

SOL

No in-app purchases

2 purchases

Vow Fasting

Subscriptions2
  • Vow Pro Monthly$4.991 Month
  • Vow Pro Annual$39.991 Year

Questions

Is SOL free?
SOL is free to download, with no in-app purchases.
Is Vow Fasting free?
Vow Fasting is free to download, with in-app purchases available.
Do SOL or Vow Fasting have ads?
Neither SOL nor Vow Fasting shows ads.
Which is updated more often, SOL or Vow Fasting?
SOL ships an update fortnightly, and Vow Fasting fortnightly. Most recently, SOL was updated on October 6, 2026 and Vow Fasting on October 6, 2026.

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