# Ultimateinstability vs FLUID X

The clearest difference is review sentiment: FLUID X at 100% against Ultimateinstability's 0%. FLUID X also leads on rating (5.0 vs 4.6). Ultimateinstability's advantage is in-app purchases (none vs 6) and update cadence (every 2 months vs every 9 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. FLUID X sells 6 in-app purchases, starting at $5.99 per month. Ultimateinstability asks for nothing beyond the download.

FLUID X holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Ultimateinstability has 9 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 0% of Ultimateinstability's written reviews are positive against 100% of FLUID X's.

Ultimateinstability ships an update every 2 months, FLUID X every 9 months. The most recent releases landed on September 29, 2026 and September 30, 2026 respectively.

## The numbers

| Metric | Ultimateinstability | FLUID X |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (9 ratings)](https://appshunter.io/ios/app/ultimateinstability/id1398788985/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/fluid-x/id6502327233/reviews)** |
| Number of ratings | **9** | 1 |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 9 months |
| Monetization | **Free** | Freemium |
| Size | 210 MB | 13 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [Ultimateinstability B.V.](https://appshunter.io/developer/1398788984) | [Fluid X Limited](https://appshunter.io/developer/1745027064) |

## What reviewers say

### Ultimateinstability

[App page](https://appshunter.io/ios/app/ultimateinstability/id1398788985)

Access over 2000 animated exercises and pre-built workout programs using specialized equipment. Connect with a community of professionals and sync your workouts with Apple Health.

**Highlights:** 180+ animated exercises, 2000+ 3D animated exercises, Pre-built workout programs, UI-community for professionals, Sync with Apple Health App

**Features:** macOS Compatibility

**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 Ultimateinstability free?

Ultimateinstability is free to download, with no in-app purchases.

### Is FLUID X free?

FLUID X is free to download, with in-app purchases available.

### Which has better reviews, Ultimateinstability or FLUID X?

FLUID X is rated higher. Ultimateinstability averages 4.6 out of 5 from 9 ratings, while FLUID X averages 5.0 from 1 ratings.

### Do Ultimateinstability or FLUID X have ads?

Neither Ultimateinstability nor FLUID X shows ads.

### Which is updated more often, Ultimateinstability or FLUID X?

Ultimateinstability ships an update every 2 months, and FLUID X every 9 months. Most recently, Ultimateinstability was updated on September 29, 2026 and FLUID X on September 30, 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.*