# Deck Builder for Union Arena vs Castlog

The clearest difference is ads: Castlog at none against Deck Builder for Union Arena's shown. On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. Deck Builder for Union Arena sells 2 in-app purchases, starting at $4.99 per month and Castlog sells 4 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

Deck Builder for Union Arena ships an update weekly, Castlog every 6 days. The most recent releases landed on October 24, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | Deck Builder for Union Arena | Castlog |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (72 ratings)](https://appshunter.io/ios/app/deck-builder-for-union-arena/id6563139619/reviews)** | — |
| Number of ratings | **72** | — |
| Positive reviews | 63.6% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Weekly | **Every 6 days** |
| Monetization | Free with in-app purchases | — |
| Size | 80 MB | 44 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 9+ | 4+ |
| Developer | [Nicholas Martin Geil](https://appshunter.io/developer/1757209176) | [W-T-F it Works](https://appshunter.io/developer/1891141140) |

## What reviewers say

### Deck Builder for Union Arena

[App page](https://appshunter.io/ios/app/deck-builder-for-union-arena/id6563139619)

This fan-made companion app helps you build, manage, and share decks for the Union Arena TCG. It features a comprehensive card database, TCGPlayer value integration, and the ability to buy cards directly within the app.

**Highlights:** Extensive card database, Deck building and management, Card scanning for collection, Community deck sharing, TCGPlayer value integration, Offline collection access

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Union Arena Pro | $4.99 | per month |
| Remove All Ads | $4.99 | one-time |


### Castlog

[App page](https://appshunter.io/ios/app/castlog-every-spell-counts/id6761730758)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Castlog Pro | $3.99 | per month |
| Castlog Playgroup+ | $6.99 | per month |
| Castlog Pro (Yearly) | $29.99 | per year |
| Castlog Playgroup+ (Yearly) | $59.99 | per year |


## Frequently asked questions

### Is Deck Builder for Union Arena free?

Deck Builder for Union Arena is free to download, with in-app purchases available.

### Is Castlog free?

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

### Do Deck Builder for Union Arena or Castlog have ads?

Deck Builder for Union Arena shows ads; Castlog does not.

### Which is updated more often, Deck Builder for Union Arena or Castlog?

Deck Builder for Union Arena ships an update weekly, and Castlog every 6 days. Most recently, Deck Builder for Union Arena was updated on October 24, 2026 and Castlog 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.*