# UD Mobile vs FieldSize

The clearest difference is in-app purchases: UD Mobile at none against FieldSize's 1. UD Mobile also leads on update cadence (weekly vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. FieldSize sells 1 in-app purchase, starting at $24.99 per year. UD Mobile asks for nothing beyond the download.

UD Mobile ships an update weekly, FieldSize every 3 months. The most recent releases landed on October 24, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | UD Mobile | FieldSize |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.1 (37 ratings)](https://appshunter.io/ios/app/ud-mobile/id1550618148/reviews)** | — |
| Number of ratings | **37** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Weekly** | Every 3 months |
| Monetization | Free | — |
| Size | 105 MB | 15 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Universal Devices, Inc.](https://appshunter.io/developer/1550618150) | [Chris Weed](https://appshunter.io/developer/1795373394) |

## What reviewers say

### UD Mobile

[App page](https://appshunter.io/ios/app/ud-mobile/id1550618148)

Control your Universal Devices home automation controllers, including eisy, Polisy, and ISY994i. Manage Insteon, Z-Wave, Zigbee devices, programs, and network resources locally or remotely. Integrates with ISY Portal for seamless remote access.

**Highlights:** Control Universal Devices controllers, Manage Insteon, Z-Wave, Zigbee devices, Control programs and variables, Local and remote connection options, ISY Portal integration

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

**In-app purchases:** none


### FieldSize

[App page](https://appshunter.io/ios/app/fieldsize/id6743102897)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Yearly | $24.99 | per year |


## Frequently asked questions

### Is UD Mobile free?

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

### Is FieldSize free?

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

### Do UD Mobile or FieldSize have ads?

Neither UD Mobile nor FieldSize shows ads.

### Which is updated more often, UD Mobile or FieldSize?

UD Mobile ships an update weekly, and FieldSize every 3 months. Most recently, UD Mobile was updated on October 24, 2026 and FieldSize on October 12, 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.*