# Castle Link vs Vacci Dropper

The clearest difference is update cadence: Castle Link at monthly against Vacci Dropper's every 2 months. Castle Link also leads on device support (3 vs 1) and iOS requirement (12.0 vs 16.0). On price, ads and in-app purchases there is nothing between them.

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

Castle Link ships an update monthly, Vacci Dropper every 2 months. The most recent releases landed on October 2, 2026 and September 27, 2026 respectively.

## The numbers

| Metric | Castle Link | Vacci Dropper |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.8 (32 ratings)](https://appshunter.io/ios/app/castle-link/id1215086336/reviews)** | — |
| Number of ratings | **32** | — |
| Positive reviews | 18.2% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Monthly** | Every 2 months |
| Monetization | Free | — |
| Size | 39 MB | 6 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Castle Creations Inc](https://appshunter.io/developer/1377811229) | [Colorado State University](https://appshunter.io/developer/527760765) |

## What reviewers say

### Castle Link

[App page](https://appshunter.io/ios/app/castle-link/id1215086336)

Wirelessly program and update settings for compatible electronic speed controllers and BEC devices. Save and sync profiles across devices, and access data logs without an internet connection.

**Highlights:** Wireless programming via Bluetooth, Firmware updates, Save and load custom profiles, Sync settings across iOS devices, Offline functionality, Data log viewing

**Features:** macOS Compatibility

**In-app purchases:** none


### Vacci Dropper

[App page](https://appshunter.io/ios/app/vacci-dropper/id6468026746)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Castle Link free?

Castle Link is free to download, with no in-app purchases.

### Is Vacci Dropper free?

Vacci Dropper is free to download, with no in-app purchases.

### Do Castle Link or Vacci Dropper have ads?

Neither Castle Link nor Vacci Dropper shows ads.

### Which is updated more often, Castle Link or Vacci Dropper?

Castle Link ships an update monthly, and Vacci Dropper every 2 months. Most recently, Castle Link was updated on October 2, 2026 and Vacci Dropper on September 27, 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.*