# Pilates Underground vs Fourth Space Studios

The clearest difference is update cadence: Fourth Space Studios at every 3 weeks against Pilates Underground's every 11 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Pilates Underground ships an update every 11 months, Fourth Space Studios every 3 weeks. The most recent releases landed on October 9, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Pilates Underground | Fourth Space Studios |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/fourth-space-studios/id6784434581/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 11 months | **Every 3 weeks** |
| Monetization | — | Free |
| Size | 121 MB | 38 MB |
| Requires iOS | 16.4 | **16.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Sutra Fitness, Inc.](https://appshunter.io/developer/914371834) | [Fourth Space Studios, Inc.](https://appshunter.io/developer/6784434583) |

## What reviewers say

### Pilates Underground

[App page](https://appshunter.io/ios/app/pilates-underground/id6753695861)

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

**In-app purchases:** none


### Fourth Space Studios

[App page](https://appshunter.io/ios/app/fourth-space-studios/id6784434581)

Browse and purchase class packs or memberships. View the schedule, filter classes by type, and book reservations. Manage upcoming classes to stay organized and committed to fitness goals.

**Highlights:** Purchase class packs and memberships, Browse class schedule, Filter classes by type, Manage class reservations, Track upcoming classes

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

**In-app purchases:** none


## Frequently asked questions

### Is Pilates Underground free?

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

### Is Fourth Space Studios free?

Fourth Space Studios is free to download, with no in-app purchases.

### Do Pilates Underground or Fourth Space Studios have ads?

Neither Pilates Underground nor Fourth Space Studios shows ads.

### Which is updated more often, Pilates Underground or Fourth Space Studios?

Pilates Underground ships an update every 11 months, and Fourth Space Studios every 3 weeks. Most recently, Pilates Underground was updated on October 9, 2026 and Fourth Space Studios on October 19, 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.*