# Castle Link vs SPM GNSS

The clearest difference is iOS requirement: SPM GNSS at 9.0 against Castle Link's 12.0. On price, ads, in-app purchases and device support there is nothing between them.

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

## The numbers

| Metric | Castle Link | SPM GNSS |
| --- | --- | --- |
| 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 | — |
| Monetization | Free | — |
| Size | 39 MB | 28 MB |
| Requires iOS | 12.0 | **9.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Castle Creations Inc](https://appshunter.io/developer/1377811229) | [Horizon Hobby](https://appshunter.io/developer/415542050) |

## 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

**What reviewers like**

- 👍 Easy to program ESC
- 👍 Data logging is fantastic
- 👍 Save profile feature is useful
- 👍 Convenient for quick setting changes

**What reviewers complain about**

- 🐛 App crashes frequently
- 🐛 App freezes often
- 🐛 Bluetooth connection issues
- 🐛 Bricks ESCs
- 🐛 Throttle curve not working

**Reported bugs**

- App crashes on passcode entry
- App freezes
- Bluetooth connection problems
- Bricking ESCs
- Throttle curve not working

**Requested features**

- Add data logging to iOS app
- Allow viewing data logs on phone
- Fix throttle curve interface
- Add Android application
- Make motor test selectable


### SPM GNSS

[App page](https://appshunter.io/ios/app/spm-gnss/id6742728543)

**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 SPM GNSS free?

SPM GNSS is free to download, with no in-app purchases.

### Do Castle Link or SPM GNSS have ads?

Neither Castle Link nor SPM GNSS shows ads.

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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.*