# Stark Bag vs FLUID X

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%) and rating (5.0 vs 4.8). Stark Bag's advantage is in-app purchases (none vs 6) and ratings volume (50 vs 1). On update cadence, ads, device support and iOS requirement there is nothing between them.

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.

## The numbers

| Metric | Stark Bag | FLUID X |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | [4.8 (50 ratings)](https://appshunter.io/ios/app/stark-bag/id887426211/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/fluid-x/id6502327233/reviews)** |
| Number of ratings | **50** | 1 |
| Positive reviews | 80.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 9 months | Every 9 months |
| Monetization | Paid | **Freemium** |
| Size | 57 MB | 13 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Postra AB](https://appshunter.io/developer/1807937957) | [Fluid X Limited](https://appshunter.io/developer/1745027064) |

## What reviewers say

### Stark Bag

[App page](https://appshunter.io/ios/app/stark-bag/id887426211)

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

**Highlights:** HD exercise videos, Customizable workout routines, Tabata, HIIT, and Circuit training timers, Progress tracking and scoring, Targeted muscle group exercises, Apple Health integration

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### FLUID X

[App page](https://appshunter.io/ios/app/fluid-x/id6502327233)

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:** macOS Compatibility

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Fluidx X Coaching Subscription | $5.99 | per month |
| FX Monthly Subscription | $19.99 | per month |
| FX Annual Subscription | $119.99 | per year |
| 99 Tank 20 & Tank 15 Library | $14.95 | one-time |
| 99 Bobas & Cube Library | $14.95 | one-time |
| FX Foundation Course | $191.99 | one-time |


## Frequently asked 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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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*