# Castle Link vs ISD Go

The clearest difference is update cadence: ISD Go at weekly against Castle Link's monthly. On price, rating, review sentiment and ratings volume there is nothing between them.

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

On the App Store both sit at effectively the same score — 1.8 for Castle Link against 1.8 for ISD Go. Both are backed by a comparable volume of ratings — 32 and 30 respectively. Written reviews split almost evenly too, at 18% and 19% positive.

Castle Link ships an update monthly, ISD Go weekly. The most recent releases landed on October 14, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | Castle Link | ISD Go |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.8 (32 ratings)](https://appshunter.io/ios/app/castle-link/id1215086336/reviews) | **[1.8 (30 ratings)](https://appshunter.io/ios/app/isd-go/id1447072980/reviews)** |
| Number of ratings | **32** | 30 |
| Positive reviews | 18.2% of reviews | **18.5% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Weekly** |
| Monetization | Free | Free |
| Size | 39 MB | 26 MB |
| Requires iOS | 12.0 | **11.0** |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Castle Creations Inc](https://appshunter.io/developer/1377811229) | [深圳艾斯特创新科技有限公司](https://appshunter.io/developer/1405370693) |

## 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


### ISD Go

[App page](https://appshunter.io/ios/app/isd-go/id1447072980)

Control and manage wireless smart devices with a user-friendly interface. Connect and operate devices via Bluetooth, and receive automatic firmware updates when new versions are available.

**Highlights:** Connect BLE smart devices, Wireless device operation, Automatic firmware detection, Firmware upgrades, User-friendly interface

**In-app purchases:** none

**What reviewers like**

- 👍 Easy firmware updates (sometimes)
- 👍 Practical app interface
- 👍 Works for some users
- 👍 Good hardware functionality (without app)

**What reviewers complain about**

- 🐛 Frequent connection drops (Bluetooth)
- 🐛 Firmware update failures
- 🐛 Device not detected
- 🐛 App crashes
- 🐛 Inaccurate readings/settings

**Reported bugs**

- App crashes during updates
- Device not recognized by app
- Abnormal network connection for firmware server
- App not updated for current iOS
- Bluetooth not reconnecting

**Requested features**

- Update app for current iOS
- Fix firmware update issues
- Improve Bluetooth connection stability
- Allow discharging to lower voltages (e.g., 0.0V)
- Increase discharge current options


## Frequently asked questions

### Is Castle Link free?

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

### Is ISD Go free?

ISD Go is free to download, with no in-app purchases.

### Which has better reviews, Castle Link or ISD Go?

ISD Go is rated higher. Castle Link averages 1.8 out of 5 from 32 ratings, while ISD Go averages 1.8 from 30 ratings.

### Do Castle Link or ISD Go have ads?

Neither Castle Link nor ISD Go shows ads.

### Which is updated more often, Castle Link or ISD Go?

Castle Link ships an update monthly, and ISD Go weekly. Most recently, Castle Link was updated on October 14, 2026 and ISD Go on October 20, 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.*