Comparison

Castle Link vs RC Speed Calculator Pro

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • Wireless programming via Bluetooth
  • Firmware updates
  • Save and load custom profiles
  • Sync settings across iOS devices
  • Offline functionality
  • Data log viewing
Features
Read full description

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)

About

RC Speed Calculator Pro

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
Read full description

Also try RC Speed Run to log and share your fastest runs! https://www.sodialed.com/apps/rc-speed-run Quickly and easily get an estimate for your RC car's top speed with RC Speed Calculator Pro! Just tell us which car you have, enter some info about your gearing, motor and batteries, and we'll do the rest. Record your estimates to compare different car setups, and if you have a speed gun, you can record your actual top speed along with the estimate. Info you'll need: - Pinion gear teeth - Battery cells (or voltage) - Motor Kv rating - Tire diameter (we can fill this in based on your car type) Info we probably have already based on your car: - Spur gear teeth - Transmission ratio Please note, our top speed estimates are just that - estimates! We use a formula that works in theory (in perfect, not real-world conditions), but every car and all driving conditions are different, so expect some variation from real measured speeds.

Screenshots

Castle Link4 screens
RC Speed Calculator Pro3 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard4 real differences · 6 level
Castle Link versus RC Speed Calculator Pro: the parameters behind the verdict, then further details
ParameterCastle LinkRC Speed Calculator Pro
PriceFreeFree
Rating1.8 (32 ratings)4.9 (23 ratings) — better
Positive reviews18.2% of reviews100.0% of reviews — better
Number of ratings32 — better23
Update frequencyMonthlyFortnightly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS12.0 — better17.0
Further details — not scored
Size39 MB160 MB
Age rating4+4+
DeveloperCastle Creations, Inc.Degree3, Inc.

Customer experience

Castle Link

All ratings32 ratings
Positive12.5%
Neutral9.4%
Negative78.1%
Written reviews44 reviews
Positive18.2%
Neutral15.9%
Negative65.9%

RC Speed Calculator Pro

All ratings23 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews10 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Castle Link

No in-app purchases

None

RC Speed Calculator Pro

No in-app purchases

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.

Other comparisons