Selcall Selective Calling Tone vs RST Scope Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Selcall Selective Calling Tone
Generate various selective calling tones for communication. Choose from over 20 tone types, queue multiple tones for burst transmission, and customize tone durations and gaps. Store frequently used sequences for quick access.
- Over 20 tone types
- Tone queuing and burst transmission
- Customizable tone duration and gap
- Memory for storing tone sequences
- CTCSS continuous tone generation
- CODAN mode for priority calls
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SelCall generates Selective Calling Tones. Select your tone type from the extensive selection of available modes, then touch the button for each tone you wish to send. You can even queue up tones and have them sent in a burst, if you wish. The following tone types can be generated: DTMF CCIR1 CCIR7 PCCIR EIA EEA CCITT EURO NATEL VDEW MODAT ZVEI1 ZVEI2 ZVEI3 PZVEI DZVEI PDZVEI ICAO ICAO SELCALL 32 CTCSS CODAN Touch the button on the upper right corner to get a list of SelCall tone modes, and select the mode you wish to use. Then touch the button for each tone you wish to generate. If you turn the switch off, you can queue up several tones (they will be displayed to the left of the switch) and then turn the switch back on to play them. Any tones that you played by turning the switch on can be repeated by tapping the RPT/Repeat button. You can also store commonly used tone sequences. Tap on the Mem button to bring of the list of memory entries, which will by empty at first. To add an entry, tap the Edit button, then the green plus sign to add an entry, which will get a default name of Untitled. Tap Done, then tap on the Untitled entry to edit it. You can change the name, as well as the tone keys to be sent. To send an entry, tap the send button. It will be sent (or stored in the buffer if the switch is off). It will also be placed in the repeat buffer, so you can tap RPT/Repeat to re-send it. The duration of tones and gap between them can be customized for most modes. Enter the values in milliseconds. The maximum allowed values are 500 milliseconds. In CTCSS mode, touch the button for the tone that you wish to continuously generate. There is a switch which turns the tone on and off, and when on, the tone will continuously play, even when you switch to another tone mode, so you can combine CTCSS with other tone modes. In CODAN mode, adjust the center frequency if necessary, select the priority of the message, and dial in the ID to call, and your ID. Then tap Send. Sequence mode allows you to create sequences of arbitrary tones. First, you will see a list of your sequences. You can use Edit to add additional sequences, delete a sequence, or re-arrange them. Three sample tone sequences are created for you, as examples. To rename a sequence, tap on it and edit the text. To edit to send a sequence, tap on the disclosure indicator at the extreme right. Each sequence is a set of lines, each of which has two numbers. The first is the frequency of the tone in Hertz, the second is the duration of the tone in milliseconds. One second is 1,000 milliseconds. Do not put an additional space between the numbers, after them, before them, or use any other characters, or the sequence will not correctly play. You can play two tones at the same time, in that case, three numbers must be entered on each line, the first two are the tone frequencies, the third is the duration. The first sample sequence, Seq 1, sends eight tones. The first is 1200 Hz for 550 milliseconds, then there are six more tones: 1100, 1000, 1100, 1000, 1100, 1000 Hz, each 200 milliseconds. Then a final tone of 1500 Hz for 350 milliseconds. To play a sequence, tap Send. To edit a line, tap on it and edit the text. You need a single space between the frequency and length. You can use Edit to add additional lines, delete a line, or re-arrange them.
RST Scope Pro
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This is an app for amateur radio operators with a narrow band of audio frequency, spectrum scope & waterfall display. You can get a rich display by microphone inputting the speaker output of a radio that does not have a spectrum scope or waterfall function. The FFT allows you to distinguish between the dot and dash of Morse code. [function] 1. Ability to change the speed of the waterfall 2. Ability to adjust the level of audio input 3. Function to switch the display band between wide and narrow 4. Display pause function (pause / cancel by touching the screen) 5. Display scaling for iPhone Display size. 6. Function to switch frequency resolution.(40Hz/20Hz/10Hz) 7. Function to switch between bar graph and line graph 8. Function to switch the cross hatch ON / OFF by longTap 9. Function to switch the USB/LSB by Left/Right Swipe 10.Recording/Playback function of Input Sound 11.File Listing function RST Scope(Free) https://www.youtube.com/watch?v=1s9RvOFp52g
Screenshots
Verdict
The clearest difference is update cadence: RST Scope Pro at every 6 days against Selcall Selective Calling Tone's every 4 months. RST Scope Pro also leads on price ($1.99 vs $2.99). Selcall Selective Calling Tone's advantage is iOS requirement (12.0 vs 15.6). On 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
Selcall Selective Calling Tone costs $2.99 and RST Scope Pro $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Selcall Selective Calling Tone ships an update every 4 months, RST Scope Pro every 6 days. The most recent releases landed on August 25, 2026 and March 12, 2026 respectively.
| Parameter | Selcall Selective Calling Tone | RST Scope Pro |
|---|---|---|
| Price | $2.99 | $1.99 — better |
| Rating | 3.2 (14 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 14 — better | — |
| Update frequency | Every 4 months | Every 6 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 2 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Black Cat Systems | koji kamogawa |
In-app purchases
Selcall Selective Calling Tone
No in-app purchases
RST Scope Pro
No in-app purchases
Questions
Is Selcall Selective Calling Tone free?
Is RST Scope Pro free?
Do Selcall Selective Calling Tone or RST Scope Pro have ads?
Which is updated more often, Selcall Selective Calling Tone or RST Scope Pro?
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