# JG Underfloor vs Sayph Space

The clearest difference is in-app purchases: JG Underfloor at none against Sayph Space's 1. Sayph Space's advantage is update cadence (every 4 weeks vs every 22 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Sayph Space sells 1 in-app purchase, starting at $2.99 per month. JG Underfloor asks for nothing beyond the download.

JG Underfloor ships an update every 22 months, Sayph Space every 4 weeks. The most recent releases landed on October 24, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | JG Underfloor | Sayph Space |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 22 months | **Every 4 weeks** |
| Monetization | Free | — |
| Size | 226 MB | 36 MB |
| Requires iOS | **14.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [Reliance Worldwide Corporation](https://appshunter.io/developer/1638011999) | [Sayph](https://appshunter.io/developer/1865514144) |

## What reviewers say

### JG Underfloor

[App page](https://appshunter.io/ios/app/jg-underfloor/id1638011997)

Control your home's underfloor heating system with this intuitive app. Manage thermostats and timers for ultimate zone control and easy configuration of both RF and hard-wired systems.

**Highlights:** Connect to John Guest thermostats, Manage timers, Zone control, Configure RF systems, Configure hard-wired systems, Intuitive user interface

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

**In-app purchases:** none


### Sayph Space

[App page](https://appshunter.io/ios/app/sayph-space/id6757244616)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sayph Space Early Adopter | $2.99 | per month |


## Frequently asked questions

### Is JG Underfloor free?

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

### Is Sayph Space free?

Sayph Space is free to download, with in-app purchases available.

### Do JG Underfloor or Sayph Space have ads?

Neither JG Underfloor nor Sayph Space shows ads.

### Which is updated more often, JG Underfloor or Sayph Space?

JG Underfloor ships an update every 22 months, and Sayph Space every 4 weeks. Most recently, JG Underfloor was updated on October 24, 2026 and Sayph Space on October 16, 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.*