A4Calc vs Black Widow Key Machine
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
A4Calc
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A4 Small Format Interchangeable Core Calculator (sister app of A2Calc and A3Calc) ---Programmed by a Locksmith, for Locksmiths--- Automatically calculates the pinning chart for A4 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
Black Widow Key Machine
This mobile tool allows locksmiths to quickly cut various types of keys, including high-security, edge-cut, dimple, tibbe, and tubular blanks. It connects via Bluetooth to a mobile device for cutting keys by code, duplicating, and progression.
- Cuts high-security keys
- Cuts edge-cut keys
- Cuts dimple keys
- Cuts tibbe keys
- Cuts tubular keys
- Bluetooth connectivity
- Cut by code functionality
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The Black Widow key machine is designed to quickly cut all keys a locksmith needs to run their business: high-security, edge-cut, dimple, tibbe, and tubular key blanks. Use your mobile device via Bluetooth to cut keys by code, duplicate, and progression your keys.
Screenshots
Verdict
The clearest difference is price: Black Widow Key Machine at Free against A4Calc's $4.99. Black Widow Key Machine also leads on update cadence (every 5 weeks vs every 8 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
Black Widow Key Machine is free to download; A4Calc costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.
A4Calc ships an update every 8 months, Black Widow Key Machine every 5 weeks. The most recent releases landed on September 30, 2026 and September 6, 2026 respectively.
| Parameter | A4Calc | Black Widow Key Machine |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | — | 4.5 (2 ratings) — better |
| Number of ratings | — | 2 — better |
| Update frequency | Every 8 months | Every 5 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 12.0 | 12.0 |
| Further details — not scored | ||
| Size | 2 MB | 149 MB |
| Age rating | 4+ | 4+ |
| Developer | Farren Domenici | American Key Supply |
In-app purchases
A4Calc
No in-app purchases
Black Widow Key Machine
No in-app purchases
Questions
Is A4Calc free?
Is Black Widow Key Machine free?
Do A4Calc or Black Widow Key Machine have ads?
Which is updated more often, A4Calc or Black Widow Key Machine?
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