Castle Link vs GACRacing
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Castle Link
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.
- Wireless programming via Bluetooth
- Firmware updates
- Save and load custom profiles
- Sync settings across iOS devices
- Offline functionality
- Data log viewing
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The Castle Link™ app enables users to wirelessly program settings and update firmware on any current Castle Creations ESC, many older models and the BEC 2.0/BEC Pro using the waterproof Castle B•LINK Bluetooth® adapter. You can quickly alter parameters and fine-tune adjustments anytime, anywhere. - Save profiles to allow for quick changes between settings - Sync information between multiple iOS devices - No data/internet connection required - The Castle Link app can be used with multiple B•LINK adapters or can store vehicle information and allow users to use one adapter on multiple vehicles - Each B•LINK is protected with a 4-digit passcode to prevent tampering with your settings - Download and View Data Logs from compatible controllers Requirements: - Castle B•LINK Bluetooth adapter (011-0135-00)
GACRacing
This application is an Electronic Speed Controller (ESC) designed for crawler cars. It offers exceptional low-speed control and broad compatibility with sensorless brushless motors. Users can switch between crawler and normal operating modes via PWM channels.
- Super smooth low-speed control
- Compatible with 99% of sensorless brushless motors
- Two operating modes: crawler and normal
- Mode switching via PWM channels
- Designed for crawler cars
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This is an ESC developed for crawler car, with a super smooth low speed and compatibility with 99% of sensorless brushless motors. It has two operating modes: crawler mode and normal mode。 G40 ESc：Running mode can be switched through AUX channel G40 Pro ESC：Real time adjustment of drag braking force through AUX channel
Screenshots
Verdict
The clearest difference is rating: GACRacing at 5.0 against Castle Link's 1.8. Castle Link's advantage is ratings volume (32 vs 2) and update cadence (monthly vs every 2 months). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
GACRacing holds the better App Store score, 5.0 against 1.8. That said, the two scores are not equally well evidenced: Castle Link has 32 ratings behind it against 2, so its average is the more settled of the two.
Castle Link ships an update monthly, GACRacing every 2 months. The most recent releases landed on October 24, 2026 and October 11, 2026 respectively.
| Parameter | Castle Link | GACRacing |
|---|---|---|
| Price | Free | Free |
| Rating | 1.8 (32 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 18.2% of reviews | — |
| Number of ratings | 32 — better | 2 |
| Update frequency | Monthly — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 39 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | Castle Creations Inc | 琪 赵 |
Customer experience
Castle Link
GACRacing
Bugs and requests
Castle Link
Reported bugs
16 issues- App crashes on passcode entry
- App freezes
- Bluetooth connection problems
- Bricking ESCs
- Throttle curve not working
Show 11 moreShow fewer
- Demo mode not functional
- Torque settings not saving
- Motor test not selectable
- Data logging issues
- Latest update causing problems
- Incompatibility with newer products
- Loading screen stuck
- Locking out ESC and beeping
- ESC not recognized by app
- Lost connection to ESC
- Firmware update failure
Requested features
9 requests- Add data logging to iOS app
- Allow viewing data logs on phone
- Fix throttle curve interface
- Add Android application
- Make motor test selectable
Show 4 moreShow fewer
- Fix data logging history clearing
- Allow firmware updates via app
- Support for newer ESCs (e.g., Copperhead)
- Allow app to work with cables
GACRacing
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Castle Link
No in-app purchases
GACRacing
No in-app purchases
