Comparison

FS8 vs Kefir

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

Head to head
About

FS8

Book fitness classes, join programs, and track your progress. Discover healthy recipes and educational content to enhance your physical and mental well-being. Achieve your fitness goals with this comprehensive wellness companion.

Highlights
  • Book and schedule fitness classes
  • Join 30-day fitness programs
  • Track progress and set goals
  • Discover healthy recipes
  • Access educational wellness articles
  • Book in-studio body scans
Features
Read full description

Cultivate strength in both body and mind with the new FS8 member app. • Book classes, join waitlists and check class schedules. • Join FS8 Programs, set goals, complete check-ins and share your results. • Discover delicious and easy to make recipes. BOOK CLASSES - Book classes, join waitlists and check class schedules. With our exclusive FS8 booking experience see all of our workout brands you know and love as well as exactly whether its a cardio, strength, recovery or hybrid day. You can also book an in-studio body scan, helping you to understand your body composition and personal fitness journey. JOIN FS8 30-DAY PROGRAMS - Designed to elevate your physical, mental, and emotional well-being. Commit to consistency by participating in 20 classes in 30 days with a focus on the 8 scientifically-backed FS8 elements. The FS8 app extends your experience beyond the studio with weekly check-Ins and educational resources. DISCOVER RECIPES - Discover delicious recipes curated by world-class dietitians. Further your understanding about nutrition and wellbeing from industry experts through constantly updated articles. Achieve your health goals and cultivate strength in both mind and body.

About

Kefir

Features
Read full description

With Kefir, tracking your nutrition and building healthy habits is fast. 4 metrics: food quality, micronutrients, gut health, macro. Forget manual calorie counting. Kefir analyzes your meals instantly from a single photo, voice note, or text description. Get deep health insights. THE 4-PILLAR SCORING SYSTEM Every meal you log gets an honest, strict 0–100 score across four independent dimensions: 1) Food Quality: Analyzes food processing (NOVA-style) to help you limit refined sugars and synthetic additives. 2) Macro Balance: Tracks your proteins, fats, and carbs against your body's personal targets. 3) Micronutrient Diversity: Encourages a colorful variety of whole, plant-based foods to maximize your vitamin intake. 4) Gut Health & Inflammation: Monitors fiber intake, ferments, and potential digestive irritants. KEY FEATURES a. Instant AI Food Scanner: Log breakfasts, lunches, and dinners via camera or dictation in seconds. No tedious database searching. b. Goal-Directed Health Briefs: Start each morning with a data-driven sync on your home screen. Discover yesterday's momentum and today's optimal adjustment lever tailored to your weight or fitness goals. c. AI-Scored Healthy Recipes: Discover curated meal ideas or input your own custom recipes to instantly analyze their nutritional pillars before you cook. d. 24/7 Personal AI Coach: Chat with a personal nutritionist. Ask for macro breakdowns, restaurant tips, or customized recipes based on your actual data. e. Smart Hydration: Separately log your water intake to unlock the final 5% of your 7-day rolling Nutrition Score. Whether your goal is sustainable weight loss, better energy, or improved digestion, Kefir adapts to your dietary preferences, allergies, and intolerances. Stop counting numbers blindly. Download Kefir today! Disclaimer: Kefir is a wellness tool for habit-building and nutrition tracking. It is not a medical device and does not diagnose or treat any medical conditions. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

FS83 screens
Kefir4 screens

Verdict

The call

The clearest difference is in-app purchases: FS8 at none against Kefir's 2. Kefir's advantage is update cadence (every 8 days vs every 4 weeks). On price, ads, device support and iOS requirement there is nothing between them.

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Kefir sells 2 in-app purchases, starting at $5.99 per month. FS8 asks for nothing beyond the download.

UpkeepUpdate frequency

FS8 ships an update every 4 weeks, Kefir every 8 days. The most recent releases landed on September 11, 2026 and September 13, 2026 respectively.

Scorecard2 real differences · 8 level
FS8 versus Kefir: the parameters behind the verdict, then further details
ParameterFS8Kefir
PriceFreeFree
Rating4.0 (20 ratings) — better—
Positive reviews66.7% of reviews—
Number of ratings20 — better—
Update frequencyEvery 4 weeksEvery 8 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.115.1
Further details — not scored
Size104 MB40 MB
Age rating4+4+
DeveloperFS8 Inc.Daniel Signer

In-app purchases

None

FS8

No in-app purchases

2 purchases

Kefir

Subscriptions2
  • Monthly$5.991 Month
  • Annual$29.991 Year

Questions

Is FS8 free?
FS8 is free to download, with no in-app purchases.
Is Kefir free?
Kefir is free to download, with in-app purchases available.
Do FS8 or Kefir have ads?
Neither FS8 nor Kefir shows ads.
Which is updated more often, FS8 or Kefir?
FS8 ships an update every 4 weeks, and Kefir every 8 days. Most recently, FS8 was updated on September 11, 2026 and Kefir on September 13, 2026.

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