Comparison

RST Decoder vs AdditionTraining

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

Head to head
About

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.

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
Read full description

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

About

AdditionTraining

Features
Read full description

正の数、負の数の足し算を4択で答えるゲームです。

Screenshots

RST Decoder4 screens
AdditionTraining2 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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

UpkeepUpdate frequency

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.

Scorecard1 real difference · 9 level
RST Decoder versus AdditionTraining: the parameters behind the verdict, then further details
ParameterRST DecoderAdditionTraining
PriceFreeFree
Rating5.0 (7 ratings) — better—
Positive reviews66.7% of reviews—
Number of ratings7 — better—
Update frequencyEvery 2 monthsEvery 2 weeks — better
AdsYesYes
In-app purchasesNoNo
MonetizationAd-supported—
DevicesiPhoneiPhone
Requires iOS17.016.0 — better
Further details — not scored
Size6 MB5 MB
Age rating17+4+
Developerkoji kamogawaKatsuhiko Yao

In-app purchases

None

RST Decoder

No in-app purchases

None

AdditionTraining

No in-app purchases

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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