# Castle Link vs RC Speed Calculator Pro

The clearest difference is review sentiment: RC Speed Calculator Pro at 100% against Castle Link's 18%. RC Speed Calculator Pro also leads on rating (4.9 vs 1.8) and update cadence (fortnightly vs monthly). Castle Link's advantage is iOS requirement (12.0 vs 17.0). On price, ratings volume, 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.

RC Speed Calculator Pro holds the better App Store score, 4.9 against 1.8. Both are backed by a comparable volume of ratings — 32 and 23 respectively. Written reviews point the same way: 18% of Castle Link's written reviews are positive against 100% of RC Speed Calculator Pro's.

Castle Link ships an update monthly, RC Speed Calculator Pro fortnightly. The most recent releases landed on June 13, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | Castle Link | RC Speed Calculator Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.8 (32 ratings)](https://appshunter.io/ios/app/castle-link/id1215086336/reviews) | **[4.9 (23 ratings)](https://appshunter.io/ios/app/rc-speed-calculator-pro/id6445860835/reviews)** |
| Number of ratings | **32** | 23 |
| Positive reviews | 18.2% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Fortnightly** |
| Monetization | Free | Free |
| Size | 39 MB | 160 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Castle Creations, Inc.](https://appshunter.io/developer/1377811229) | [Degree3, Inc.](https://appshunter.io/developer/1497876563) |

## 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


### RC Speed Calculator Pro

[App page](https://appshunter.io/ios/app/rc-speed-calculator-pro/id6445860835)

Estimate your RC car's top speed by inputting details about its gearing, motor, and batteries. Record your estimates and actual speeds to compare different setups.

**Highlights:** Estimate RC car top speed, Input gearing, motor, and battery info, Record speed estimates, Log actual top speeds, Compare different car setups, Pre-filled car data

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

**In-app purchases:** none


## Frequently asked questions

### Is Castle Link free?

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

### Is RC Speed Calculator Pro free?

RC Speed Calculator Pro is free to download, with no in-app purchases.

### Which has better reviews, Castle Link or RC Speed Calculator Pro?

RC Speed Calculator Pro is rated higher. Castle Link averages 1.8 out of 5 from 32 ratings, while RC Speed Calculator Pro averages 4.9 from 23 ratings.

### Do Castle Link or RC Speed Calculator Pro have ads?

Neither Castle Link nor RC Speed Calculator Pro shows ads.

### Which is updated more often, Castle Link or RC Speed Calculator Pro?

Castle Link ships an update monthly, and RC Speed Calculator Pro fortnightly. Most recently, Castle Link was updated on June 13, 2026 and RC Speed Calculator Pro on September 23, 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.*