# The Stack System vs Fiix Body

The clearest difference is in-app purchases: Fiix Body at none against The Stack System's 8. Fiix Body also leads on device support (3 vs 1). The Stack System's advantage is review sentiment (86% vs 67%) and ratings volume (7K vs 297). On price, update cadence, ads and iOS requirement there is nothing between them.

Both are free to download. The Stack System sells 6 in-app purchases, starting at $9.99 per 7 days. Fiix Body asks for nothing beyond the download.

The Stack System holds the better App Store score, 4.9 against 4.7. That said, the two scores are not equally well evidenced: The Stack System has 7K ratings behind it against 297, so its average is the more settled of the two. Written reviews point the same way: 86% of The Stack System's written reviews are positive against 67% of Fiix Body's.

The Stack System ships an update monthly, Fiix Body every 5 weeks. The most recent releases landed on October 1, 2026 and June 9, 2026 respectively.

## The numbers

| Metric | The Stack System | Fiix Body |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (7K ratings)](https://appshunter.io/ios/app/the-stack-system/id1534757407/reviews)** | [4.7 (297 ratings)](https://appshunter.io/ios/app/fiix-body/id1562886855/reviews) |
| Number of ratings | **7K** | 297 |
| Positive reviews | **86.3% of reviews** | 66.7% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Monthly** | Every 5 weeks |
| Monetization | Freemium | **Free** |
| Best chart rank | **#156** | — |
| Size | 213 MB | 33 MB |
| Requires iOS | 16.2 | **15.6** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [The Stack System, LP](https://appshunter.io/developer/1534757409) | [Fiix Body](https://appshunter.io/developer/1850967876) |

## What reviewers say

### The Stack System

[App page](https://appshunter.io/ios/app/the-stack-system/id1534757407)

**Currently charting:** #156 Top Grossing · Health & Fitness (US App Store)

Enhance your golf game with science-based training modules for speed, wedging, and putting. Improve distance, accuracy, and consistency with personalized practice sessions and detailed analytics. Requires compatible hardware.

**Highlights:** Variable inertia speed training for distance, Science-based wedge distance control, Gamified putting practice and analytics, Personalized practice sessions, Real-time scoring and insights, Customizable training modes

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Stack Putting 1 Week | $9.99 | per 7 days |
| Stack Putting 1 Wk | $9.99 | per 7 days |
| TheStack Speed Training | $14.99 | per 7 days |
| TheStack Scoring Membership | $99.00 | per year |
| TheStack Speed Membership | $99.00 | per year |
| TheStack Premium Membership | $129.00 | per year |

**What reviewers like**

- 🚀 Seeing speed gains
- 👍 Easy to use app
- 👍 Motivating and helpful
- 👍 Detailed instructions
- 👍 Warmup routine

**What reviewers complain about**

- 🐛 Glitchy app (audio, dictation, timers)
- 🔧 Integration issues with other devices
- 💡 More insights and advice needed
- 🐛 Inconsistent audio/voice features
- 🐛 Occasional missing countdown

**Reported bugs**

- Putting app not working properly
- Slope percentage input issue

**Requested features**

- Calendar integration
- Music/podcast playback integration
- Apple Watch support


### Fiix Body

[App page](https://appshunter.io/ios/app/fiix-body/id1562886855)

This digital physical therapist guides you through elbow pain recovery at home. It provides personalized therapy schedules, tracks your progress with data and surveys, and offers helpful tips and videos to maximize your treatment experience.

**Highlights:** Personalized therapy schedules, Progress tracking and weekly scores, Pain assessment surveys, Comparison graphs with other users, Helpful tips and video guides, Push notification reminders

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is The Stack System free?

The Stack System is free to download, with in-app purchases available.

### Is Fiix Body free?

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

### Which has better reviews, The Stack System or Fiix Body?

The Stack System is rated higher. The Stack System averages 4.9 out of 5 from 7K ratings, while Fiix Body averages 4.7 from 297 ratings.

### Do The Stack System or Fiix Body have ads?

Neither The Stack System nor Fiix Body shows ads.

### Which is updated more often, The Stack System or Fiix Body?

The Stack System ships an update monthly, and Fiix Body every 5 weeks. Most recently, The Stack System was updated on October 1, 2026 and Fiix Body on June 9, 2026.

---

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