Comparison

A3Calc vs RST Scope Pro

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

Head to head
About

A3Calc

Features
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A3 Small Format Interchangeable Core Calculator (sister app of A2Calc and A4Calc) ---Programmed by a Locksmith, for Locksmiths--- Automatically calculates the pinning chart for A3 SFIC. Built for 6 or 7 pin systems, however, less can be achieved by using a decimal to erase a chamber. Minimum of a control and master key are required to make a chart. Additional change key available for all devices; 2 change keys available for 16:9 screen devices. Randomize function will generate completely random charts each time it is triggered. "Lock/Unlock" toggle disables/enables all inputs and functions to prevent unwanted/lost changes. Control Finder is an added bonus by reverse engineering a core to determine the control key's bitting. This is perfect when needing to remove multiple cores in a building when the control key has been lost. There are two methods for achieving the control key: 1. using the master, control, and bottom pins, or 2. using only the top/driver pins. Up to 16 different projects can be saved at any one given time. All projects are encrypted and protected with a passcode when stored on your device. All projects can be exported via AirPrint and Email. Compatibility: iPhone / iPod touch on iOS 8.0 or later and iPad on iOS 12.0 or later. Found a bug? Something not working? Have a suggestion? Feel free to contact me via email: farren@phoxlocks.com

About

RST Scope Pro

Read full description

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

A3Calc4 screens
RST Scope Pro4 screens

Verdict

The call

The clearest difference is update cadence: RST Scope Pro at every 6 days against A3Calc's every 18 months. A3Calc's advantage is iOS requirement (12.0 vs 15.6). 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

A3Calc costs $1.99 and RST Scope Pro $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

A3Calc ships an update every 18 months, RST Scope Pro every 6 days. The most recent releases landed on October 26, 2026 and October 27, 2026 respectively.

Scorecard2 real differences · 4 level
A3Calc versus RST Scope Pro: the parameters behind the verdict, then further details
ParameterA3CalcRST Scope Pro
Price$1.99$1.99
Update frequencyEvery 18 monthsEvery 6 days — better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPodiPhone, iPod
Requires iOS12.0 — better15.6
Further details — not scored
Size2 MB1 MB
Age rating4+4+
DeveloperFarren Domenicikoji kamogawa

In-app purchases

None

A3Calc

No in-app purchases

None

RST Scope Pro

No in-app purchases

Questions

Is A3Calc free?
A3Calc costs $1.99, with no in-app purchases.
Is RST Scope Pro free?
RST Scope Pro costs $1.99, with no in-app purchases.
Do A3Calc or RST Scope Pro have ads?
Neither A3Calc nor RST Scope Pro shows ads.
Which is updated more often, A3Calc or RST Scope Pro?
A3Calc ships an update every 18 months, and RST Scope Pro every 6 days. Most recently, A3Calc was updated on October 26, 2026 and RST Scope Pro on October 27, 2026.

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