A3Calc vs RST Scope Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
A3Calc
Read full descriptionHide full description
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
RST Scope Pro
Read full descriptionHide 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
Verdict
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
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.
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.
| Parameter | A3Calc | RST Scope Pro |
|---|---|---|
| Price | $1.99 | $1.99 |
| Update frequency | Every 18 months | Every 6 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 12.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 2 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Farren Domenici | koji kamogawa |
In-app purchases
A3Calc
No in-app purchases
RST Scope Pro
No in-app purchases









