# 回路計算機 vs RST Decoder Pro

The clearest difference is update cadence: RST Decoder Pro at monthly against 回路計算機's every 15 months. 回路計算機's advantage is device support (3 vs 1) and iOS requirement (13.0 vs 17.0). On price, review sentiment, ads and in-app purchases there is nothing between them.

回路計算機 costs $1.99 and RST Decoder Pro $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

回路計算機 ships an update every 15 months, RST Decoder Pro monthly. The most recent releases landed on September 21, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | 回路計算機 | RST Decoder Pro |
| --- | --- | --- |
| Price | $1.99 | $1.99 |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rst-decoder-pro/id1521025545/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 50.0% of reviews | 50.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Monthly** |
| Monetization | — | Paid |
| Size | 15 MB | 1 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [Yoshiaki Onishi](https://appshunter.io/developer/852893746) | [koji kamogawa](https://appshunter.io/developer/1488210713) |

## What reviewers say

### 回路計算機

[App page](https://appshunter.io/ios/app/id1081762110)

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

**In-app purchases:** none


### RST Decoder Pro

[App page](https://appshunter.io/ios/app/rst-decoder-pro/id1521025545)

This application decodes Morse code from your device's microphone, offering two decoding methods (BPF and FFT) with adjustable parameters. It includes features like automatic frequency detection, gain control, and real-time signal display for accurate Morse code practice and reception.

**Highlights:** Microphone Morse code decoding, BPF and FFT decoding methods, Auto Frequency Detector (AFD), Auto Gain Control (AGC), Real-time CW signal display, Waterfall display (Pro version), Adjustable control parameters

**In-app purchases:** none


## Frequently asked questions

### Is 回路計算機 free?

回路計算機 costs $1.99, with no in-app purchases.

### Is RST Decoder Pro free?

RST Decoder Pro costs $1.99, with no in-app purchases.

### Do 回路計算機 or RST Decoder Pro have ads?

Neither 回路計算機 nor RST Decoder Pro shows ads.

### Which is updated more often, 回路計算機 or RST Decoder Pro?

回路計算機 ships an update every 15 months, and RST Decoder Pro monthly. Most recently, 回路計算機 was updated on September 21, 2026 and RST Decoder Pro on September 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.*