Comparison

Stark Bag vs FLUID X

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

Head to head
About

Stark Bag

This app offers a virtual training experience with HD exercise videos and customizable workout plans. It supports various training styles like Tabata and HIIT, tracks progress, and integrates with Apple Health to log burned calories and completed workouts.

Highlights
  • HD exercise videos
  • Customizable workout plans
  • Tabata, HIIT, and Circuit training timers
  • Progress tracking and scoring
  • Targeted muscle group exercises
  • Apple Health integration
Features
Read full description

Optimize your results with Virtual Trainer Bag! - Be inspired by 27 exercises presented in sharp HD video. - Create your own personal workout. - Get a full body workout with exercises in all ranges of difficulty - While working out, follow the step by step workout-feature which take you through the workout using timers and your chosen specifics. - The timers support different workout types including Tabata, HIIT and Circuit training. - Challenge yourself, get rewards and keep track of your score. - Find exercises targeting specific muscle groups. Integration with Apple Health: Save burned calories and performed workouts. The Bag, is a crescent-shaped exercise equipment used in strength training, plyometric weight training, cardiovascular training, and general physical fitness. Exercises are performed by the professional instructor, Martin Söderblom.

About

FLUID X

This app guides users through aqua bag workouts, offering structured programs and an extensive exercise library. It caters to beginners, functional training enthusiasts, seniors, rehab clients, athletes, and cardio fans, emphasizing dynamic resistance for enhanced core stability and functional strength.

Highlights
  • Structured FX Fitness Programs
  • Extensive FX Exercise Library with video demonstrations
  • Educational resources on water bag fitness
  • Trainer tools
  • Dynamic resistance training guidance
  • Core stability and balance enhancement
Features
Read full description

Transform your fitness with Fluid X, your ultimate guide to the aqua bag workout! Master water bag fitness with expert guidance, engaging programs, and a comprehensive exercise library designed for the unique challenge of Fluid X Aqua Bags. Who is the Fluid X App For? This app is your essential companion, whether you're: - New to Aqua Bags: Start strong with foundational knowledge and introductory water bag fitness programs. - Functional Training Enthusiasts: Elevate your routine with exercises leveraging dynamic resistance for real-world strength. - Seniors: Discover joint-friendly movement routines perfect for senior fitness and maintaining mobility. - Rehab Clients: Utilize adaptable rehab exercises with controlled, progressive resistance tailored to recovery needs. - Athletes: Enhance performance by building exceptional core stability and functional power. - Cardio Fans: Get your heart pumping with fun, dance-inspired routines using the unique properties of Aqua Bags. What the Fluid X App Offers: - FX Fitness Programs: Access a growing library of structured workout programs, incorporating functional training principles for various goals (strength, cardio, mobility), all utilizing Fluid X's dynamic resistance. - FX Exercise Library: Explore hundreds of exercises with clear video demonstrations. Filter by functional training patterns (squat, hinge, push, pull, etc.), equipment, or difficulty. Find specific drills to target goals like core stability or power development. - Educational Resources: Deepen your understanding of water bag fitness with tips on technique, the science behind dynamic resistance, and how to maximize your aqua bag workout. - Trainer Tools: Resources designed for professionals integrating Fluid X. Experience the Unique Benefits: Unlock a new level of fitness by leveraging the power of Fluid X: - Dynamic Resistance: The shifting water provides constant neuromuscular challenge, leading to greater muscle activation. - Enhanced Core Stability: Naturally strengthen your core as it works constantly to control the unpredictable load. - Improved Balance & Coordination: Enhance proprioception as your body adapts to the fluid movement. - True Functional Training: Build practical strength that translates directly to daily life and athletic performance. - Versatility: Perfect for diverse needs, from foundational rehab exercises and senior fitness to high-intensity athletic training. - Fun & Engaging: The interactive nature of the aqua bag workout keeps you motivated. Download the Fluid X App today and revolutionize your fitness journey with dynamic resistance training! Terms of use: https://www.thefluidx.com/en-au/pages/terms-conditions Privacy Policy: https://movement.so/legal/privacy-policy

Screenshots

Stark Bag4 screens
FLUID X4 screens

Verdict

The call

The clearest difference is price: FLUID X at Free against Stark Bag's $4.99. FLUID X also leads on review sentiment (100% vs 80%). Stark Bag's advantage is in-app purchases (none vs 6) and ratings volume (50 vs 1). On rating, update cadence, ads and device support 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

FLUID X is free to download; Stark Bag costs $4.99 up front. FLUID X sells 6 in-app purchases, starting at $5.99 per month. Stark Bag asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

FLUID X holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Stark Bag has 50 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 80% of Stark Bag's written reviews are positive against 100% of FLUID X's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 9 months. The most recent releases landed on November 13, 2026 and November 4, 2026 respectively.

Scorecard5 real differences · 5 level
Stark Bag versus FLUID X: the parameters behind the verdict, then further details
ParameterStark BagFLUID X
Price$4.99Free — better
Rating4.8 (50 ratings)5.0 (1 ratings) — better
Positive reviews80.0% of reviews100.0% of reviews — better
Number of ratings50 — better1
Update frequencyEvery 9 monthsEvery 9 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFreemium — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.115.1
Further details — not scored
Size57 MB13 MB
Age rating4+4+
DeveloperPostra ABFluid X Limited

Customer experience

Stark Bag

All ratings50 ratings
Positive96.0%
Neutral2.0%
Negative2.0%
Written reviews10 reviews
Positive80.0%
Neutral10.0%
Negative10.0%

FLUID X

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Stark Bag

No in-app purchases

6 purchases

FLUID X

Subscriptions3
  • Fluidx X Coaching Subscription$5.991 Month
  • FX Monthly Subscription7 Days trial$19.991 Month
  • FX Annual Subscription7 Days trial$119.991 Year
One-time3
  • 99 Tank 20 & Tank 15 Library$14.95
  • 99 Bobas & Cube Library$14.95
  • FX Foundation Course$191.99

Questions

Is Stark Bag free?
Stark Bag costs $4.99, with no in-app purchases.
Is FLUID X free?
FLUID X is free to download, with in-app purchases available.
Which has better reviews, Stark Bag or FLUID X?
FLUID X is rated higher. Stark Bag averages 4.8 out of 5 from 50 ratings, while FLUID X averages 5.0 from 1 ratings.
Do Stark Bag or FLUID X have ads?
Neither Stark Bag nor FLUID X shows ads.
Which is updated more often, Stark Bag or FLUID X?
Stark Bag ships an update every 9 months, and FLUID X every 9 months. Most recently, Stark Bag was updated on November 13, 2026 and FLUID X on November 4, 2026.

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