Comparison

Selcall Selective Calling Tone vs T15 Controller

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

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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.

About

T15 Controller

Features
Read full description

Using the 'T15 Controller' app on their iPhone, user can now turn 'on' (activate) or turn 'off' (deactivate) their miniature T15 radio frequency transmitter. Previously, either external magnets (for reed switch on/off control) or a separate light control box were necessary.   The pulses of light transmitted by the iPhone's camera flash contain an embedded code that only T15 transmitters understand. Because the LED flash is so bright and the code is very complex there is no worry that the T15 transmitters will be accidentally receive a command via any other indoor or outdoor light source. In order to reduce the size of the T15 wildlife tracking transmitter (to the smallest size telemetry transmitter in the world) conventional activation and deactivation devices (such as magnetically controlled reed switches) had to be abandoned. This also gives biologists the added convenience of being able to control their T15 transmitters with a device that is normally with them all of the time...their iPhone!

Screenshots

Selcall Selective Calling Tone4 screens
T15 Controller2 screens

Verdict

The call

The clearest difference is price: T15 Controller at Free against Selcall Selective Calling Tone's $2.99. Selcall Selective Calling Tone's advantage is update cadence (every 4 months vs every 9 months). On ads, in-app purchases, device support and iOS requirement 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

T15 Controller is free to download; Selcall Selective Calling Tone costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Selcall Selective Calling Tone ships an update every 4 months, T15 Controller every 9 months. The most recent releases landed on October 13, 2026 and September 28, 2026 respectively.

Scorecard2 real differences · 8 level
Selcall Selective Calling Tone versus T15 Controller: the parameters behind the verdict, then further details
ParameterSelcall Selective Calling ToneT15 Controller
Price$2.99Free — better
Rating3.2 (14 ratings) — better—
Positive reviews50.0% of reviews—
Number of ratings14 — better—
Update frequencyEvery 4 months — betterEvery 9 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS12.011.3 — better
Further details — not scored
Size2 MB10 MB
Age rating4+4+
DeveloperBlack Cat SystemsAdvanced Telemetry Systems, Inc.

In-app purchases

None

Selcall Selective Calling Tone

No in-app purchases

None

T15 Controller

No in-app purchases

Questions

Is Selcall Selective Calling Tone free?
Selcall Selective Calling Tone costs $2.99, with no in-app purchases.
Is T15 Controller free?
T15 Controller is free to download, with no in-app purchases.
Do Selcall Selective Calling Tone or T15 Controller have ads?
Neither Selcall Selective Calling Tone nor T15 Controller shows ads.
Which is updated more often, Selcall Selective Calling Tone or T15 Controller?
Selcall Selective Calling Tone ships an update every 4 months, and T15 Controller every 9 months. Most recently, Selcall Selective Calling Tone was updated on October 13, 2026 and T15 Controller on September 28, 2026.

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