# Home Assistant vs Z21

The clearest difference is rating: Home Assistant at 4.7 against Z21's 3.8. Home Assistant also leads on in-app purchases (none vs 1) and ratings volume (4K vs 13). Z21's advantage is iOS requirement (12.0 vs 16.4). On price, ads and device support there is nothing between them.

Both are free to download. Z21 sells 1 one-off in-app purchase. Home Assistant asks for nothing beyond the download.

Home Assistant holds the better App Store score, 4.7 against 3.8. That said, the two scores are not equally well evidenced: Home Assistant has 4K ratings behind it against 13, so its average is the more settled of the two. Written reviews point the same way: 54% of Home Assistant's written reviews are positive against 38% of Z21's.

Home Assistant ships an update every 10 days, Z21 every 3 weeks. The most recent releases landed on October 26, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Home Assistant | Z21 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (4K ratings)](https://appshunter.io/ios/app/home-assistant/id1099568401/reviews)** | [3.8 (13 ratings)](https://appshunter.io/ios/app/z21/id1114706450/reviews) |
| Number of ratings | **4K** | 13 |
| Positive reviews | **54.3% of reviews** | 38.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 3 weeks |
| Monetization | **Free** | Free with in-app purchases |
| Size | 229 MB | 232 MB |
| Requires iOS | 16.4 | **12.0** |
| Devices | **iPhone, iPad, Mac, Apple Watch** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nabu Casa, Inc](https://appshunter.io/developer/1525301324) | [Modelleisenbahn GmbH](https://appshunter.io/developer/533805542) |

## What reviewers say

### Home Assistant

[App page](https://appshunter.io/ios/app/home-assistant/id1099568401)

Control your entire smart home from one app, locally and privately. Automate devices, receive notifications, and manage your home's data securely. Integrates with thousands of smart devices and open standards.

**Highlights:** Control entire home from one app, Discover and configure new devices, Automate device actions, Local data privacy, Connect to open standards (Z-Wave, Zigbee, Matter), Remote access via Home Assistant Cloud, Location-based automation

**Features:** Siri integration, Apple Watch app, Vision Pro support

**In-app purchases:** none


### Z21

[App page](https://appshunter.io/ios/app/z21/id1114706450)

Control your model train layout and locomotives wirelessly from your iOS device. Manage your locomotive library, program digital components, and operate switches and signals with an intuitive touch interface. Enjoy a realistic train control experience with customizable driver cabs.

**Highlights:** Wireless control of locomotives and layout, Manage locomotive library with images, Program digital components, Intuitive graphic interface for switches and signals, Downloadable driver cabs for realistic control, Demo mode available

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Z21 Full Version | $17.99 | one-time |

**What reviewers like**

- 👍 Intuitive and user-friendly interface
- 🚀 Fast and reliable locomotive control
- 💡 Innovative layout design with schematic control station
- 🎨 Clean, modern orange and black design
- 📱 Works seamlessly across multiple iOS devices

**What reviewers complain about**

- 🐛 Frequent app crashes and freezes
- 🔌 Connection drops to Z21 control station
- ⚠️ White screen startup issues in recent updates
- 🎮 Throttle display bugs showing incorrect speeds
- 📉 Slow performance on older devices

**Reported bugs**

- App crashes on startup (white screen issue)
- Connection drops to Z21 central station
- Throttle display shows incorrect or blank speeds
- Function buttons not responding properly in multitraction mode
- Route synchronization failures across multiple control station pages

**Requested features**

- Offline locomotive database access
- Dark mode or customizable color schemes
- Background image support for layout design
- Turntable/rotary module support
- Automatic event-based control (occupancy detection, crossing automation)


## Frequently asked questions

### Is Home Assistant free?

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

### Is Z21 free?

Z21 is free to download, with in-app purchases available.

### Which has better reviews, Home Assistant or Z21?

Home Assistant is rated higher. Home Assistant averages 4.7 out of 5 from 4K ratings, while Z21 averages 3.8 from 13 ratings.

### Do Home Assistant or Z21 have ads?

Neither Home Assistant nor Z21 shows ads.

### Which is updated more often, Home Assistant or Z21?

Home Assistant ships an update every 10 days, and Z21 every 3 weeks. Most recently, Home Assistant was updated on October 26, 2026 and Z21 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.*