Stark Bag vs FLUID X
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- HD exercise videos
- Customizable workout plans
- Tabata, HIIT, and Circuit training timers
- Progress tracking and scoring
- Targeted muscle group exercises
- Apple Health integration
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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.
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.
- 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
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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
Verdict
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
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.
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.
Both ship on a similar rhythm, roughly every 9 months. The most recent releases landed on November 13, 2026 and November 4, 2026 respectively.
| Parameter | Stark Bag | FLUID X |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 4.8 (50 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 80.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 50 — better | 1 |
| Update frequency | Every 9 months | Every 9 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Freemium — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.1 | 15.1 |
| Further details — not scored | ||
| Size | 57 MB | 13 MB |
| Age rating | 4+ | 4+ |
| Developer | Postra AB | Fluid X Limited |
Customer experience
Stark Bag
FLUID X
In-app purchases
Stark Bag
No in-app purchases
FLUID X
- Fluidx X Coaching Subscription$5.991 Month
- FX Monthly Subscription7 Days trial$19.991 Month
- FX Annual Subscription7 Days trial$119.991 Year
- 99 Tank 20 & Tank 15 Library$14.95
- 99 Bobas & Cube Library$14.95
- FX Foundation Course$191.99









