A2Calc is a specialized calculator designed for locksmiths, specifically focusing on the Small Format Interchangeable Core (SFIC) systems. This app, created by a locksmith named Farren Domenici, automates the process of generating pinning charts for 6 or 7 pin systems. It offers the flexibility to work with fewer pins by utilizing decimals to erase chambers, making it versatile for various scenarios.

One standout feature of A2Calc is its Control Finder function, which allows locksmiths to reverse engineer a core to determine the control key's bitting. This feature is particularly useful in situations where the control key is lost, enabling efficient core removal. The app also provides the ability to save up to 16 projects, encrypting them for security, and offers convenient sharing options via AirPrint or email.