Comparison

SOL vs FastLyfe

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

Head to head
About

SOL

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SOL (솔) β€” 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 β€” in real time. As you fast, SOL guides you through each biological phase: Fed State β†’ Insulin Dropping β†’ Fat Burning β†’ Ketosis β†’ Autophagy β†’ Deep Autophagy β†’ Growth Hormone Surge β†’ Immune Reset FEATURES β€’ Beautiful minimal timer with progress ring β€’ Real-time body phase updates with scientific sources β€’ Full body timeline β€” see all 8 phases and your progress β€’ Tap any phase for in-depth science and PubMed sources β€’ Smart notifications at each milestone β€’ Stats dashboard β€” track your fasting journey β€’ Background timer β€” keeps running when you close the app β€’ Light & dark mode with handcrafted watercolor textures β€’ Home screen widget β€’ Community pulse β€” you're not fasting alone β€’ 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

FastLyfe

Features
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FastLyfe: Fasting Tracker & Timer FastLyfe is an easy-to-use fasting tracker designed to help you stay consistent and build better habits. Track your fasts, follow popular fasting schedules, and monitor your progress over timeβ€”all in one simple app. Features: Fasting timer to track your sessions Popular protocols like 16:8, 18:6, and OMAD Custom fasting schedules Progress tracking and history Calendar view to see your consistency Clean and simple design FastLyfe is built for anyone looking to stay on track with intermittent fasting without distractions or unnecessary complexity.

Screenshots

SOL4 screens
FastLyfe4 screens

Verdict

The call

The clearest difference is in-app purchases: SOL at none against FastLyfe's 3. SOL also leads on update cadence (fortnightly vs every 6 weeks). FastLyfe's advantage is iOS requirement (13.0 vs 16). On price, ads and device support there is nothing between them.

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

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

Both are free to download. FastLyfe sells 3 in-app purchases, starting at $5.99 per month. SOL asks for nothing beyond the download.

UpkeepUpdate frequency

SOL ships an update fortnightly, FastLyfe every 6 weeks. The most recent releases landed on September 22, 2026 and September 19, 2026 respectively.

Scorecard3 real differences Β· 3 level
SOL versus FastLyfe: the parameters behind the verdict, then further details
ParameterSOLFastLyfe
PriceFreeFree
Update frequencyFortnightly β€” betterEvery 6 weeks
AdsNoNo
In-app purchasesNo β€” betterYes
DevicesiPhone, iPodiPhone, iPad, iPod β€” better
Requires iOS1613.0 β€” better
Further details β€” not scored
Size6 MB31 MB
Age rating4+4+
DeveloperDanny LinsnerCayden Williams

In-app purchases

None

SOL

No in-app purchases

3 purchases

FastLyfe

Subscriptions2
  • Monthly3 Days trial$5.991 Month
  • Yearly$16.991 Year
One-time1
  • Lifetime Pro$29.99

Questions

Is SOL free?
SOL is free to download, with no in-app purchases.
Is FastLyfe free?
FastLyfe is free to download, with in-app purchases available.
Do SOL or FastLyfe have ads?
Neither SOL nor FastLyfe shows ads.
Which is updated more often, SOL or FastLyfe?
SOL ships an update fortnightly, and FastLyfe every 6 weeks. Most recently, SOL was updated on September 22, 2026 and FastLyfe on September 19, 2026.

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