RST Decoder vs AdditionTraining
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RST Decoder
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.
- 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
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This is an App that decodes Morse code input from the microphone. It is a Morse practice App that you can use to check if you are keying the correct code. Signals with good S/N can be decoded correctly, but signals with bad S/N cannot be decoded correctly. Also, the performance will be degraded for extremely slow or fast signals. Usually about 5 to 10 characters are required for speed synchronization of Morse Code. Adjust the input signal so that the peak value changes from level 6 to level 7. Make fine adjustments to each parameter according to the reception status. [Additional Functions] -In addition to the decoder using BPF, a new decoder using FFT has been added so that it can be switched according to the usage. -AFD (Auto Frequency Detector) function has been added to the decoder using BPF, and BPF can be set automatically by pressing the AFD button. -The decoder using FFT automatically follows the strongest signal in the band by AFD (Auto Frequency Detector) and AGC (Auto Gain Control). You can also hold the AFD / AGC parameters by pressing the Lock button. * There will be a time lag of about 1 to 2 seconds for AFD tracking. [Control parameters] 1. Audio Input Level 2.BPF ON/OFF 3.BPF of Center Frequency 4.BPF of Band Width 5.CW Speed Control ON/OFF 6.CW Speed Control Low, Mid1, Mid2 or High 7.Delete All Decoded Text 8.Realtime CW Signal Display 9.Input signal recording / playback function *Japanese/KANA text is not supported. [Note] Since the signal after BPF is output to the audio output, it can also be used as an AF-CW filter. [URL of this App working example video] https://youtu.be/Pwp7W4m-m34
AdditionTraining
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正の数、負の数の足し算を4択で答えるゲームです。
Screenshots
Verdict
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.
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.
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.
| Parameter | RST Decoder | AdditionTraining |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (7 ratings) — better | — |
| Positive reviews | 66.7% of reviews | — |
| Number of ratings | 7 — better | — |
| Update frequency | Every 2 months | Every 2 weeks — better |
| Ads | Yes | Yes |
| In-app purchases | No | No |
| Monetization | Ad-supported | — |
| Devices | iPhone | iPhone |
| Requires iOS | 17.0 | 16.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 5 MB |
| Age rating | 17+ | 4+ |
| Developer | koji kamogawa | Katsuhiko Yao |
In-app purchases
RST Decoder
No in-app purchases
AdditionTraining
No in-app purchases
Questions
Is RST Decoder free?
Is AdditionTraining free?
Do RST Decoder or AdditionTraining have ads?
Which is updated more often, RST Decoder or AdditionTraining?
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