# RST Decoder vs AdditionTraining

The clearest difference is update cadence: AdditionTraining at every 2 weeks against RST Decoder's every 2 months. On price, ads, in-app purchases and device support there is nothing between them.

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

RST Decoder ships an update every 2 months, AdditionTraining every 2 weeks. The most recent releases landed on September 8, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | RST Decoder | AdditionTraining |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (7 ratings)](https://appshunter.io/ios/app/rst-decoder/id1519587362/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | 66.7% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | Ad-supported | — |
| Size | 6 MB | 5 MB |
| Requires iOS | 17.0 | **16.0** |
| Devices | iPhone | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [koji kamogawa](https://appshunter.io/developer/1488210713) | [Katsuhiko Yao](https://appshunter.io/developer/1543188534) |

## What reviewers say

### RST Decoder

[App page](https://appshunter.io/ios/app/rst-decoder/id1519587362)

This application decodes Morse code from your microphone, acting as a practice tool to verify your keying accuracy. It offers advanced features like BPF and FFT decoders with automatic frequency and gain control, allowing for fine-tuning of reception parameters.

**Highlights:** Microphone Morse code decoding, Morse practice and keying check, BPF and FFT decoder options, Auto Frequency Detector (AFD), Auto Gain Control (AGC), Real-time CW signal display, Input signal recording/playback

**In-app purchases:** none


### AdditionTraining

[App page](https://appshunter.io/ios/app/additiontraining/id6477338237)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RST Decoder free?

RST Decoder is free to download, with no in-app purchases.

### Is AdditionTraining free?

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

### Do RST Decoder or AdditionTraining have ads?

Both RST Decoder and AdditionTraining show ads.

### Which is updated more often, RST Decoder or AdditionTraining?

RST Decoder ships an update every 2 months, and AdditionTraining every 2 weeks. Most recently, RST Decoder was updated on September 8, 2026 and AdditionTraining on September 24, 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.*