A .app file is essentially a macOS application bundle. It’s a directory that contains all the necessary files for a macOS application to run, such as executable binaries, property list (plist) files, resources, and libraries. Despite appearing as a single file on macOS, it is actually a folder with a structured format, which allows applications to bundle their executables along with related resources like images, localizations, and configuration files.
The .app bundle is typically accessed through the Finder interface as a single application icon, but you can view its contents by right-clicking the icon and selecting “Show Package Contents.” This structure helps keep application-related files organized and encapsulated, making installation, execution, and removal straightforward.
Requirements
- Purchase an SSL.com Code Signing Certificate or Extended Validation (EV) Code Signing Certificate
 - Enroll your code signing certificate in eSigner
 - Download and install eSigner CKA
 
Steps to Sign
- Download Dynamics.365.BC.55195.US.DVD.zip at https://www.microsoft.com/en-US/download/details.aspx?id=105113 
Note: If you attempt to sign a .app file using eSigner CKA without first installing Microsoft Dynamics 365 Business Central application, you will get this SignTool error: This file format cannot be signed because it is not recognized. - Open the Dynamics.365.BC.55195.US.DVD.zip and extract the contents to your preferred location.
 - Open setup.exe for Microsoft Dynamics 365 Business Central and click the Next > button.
 - Read the Microsoft Software License Terms and then click the I accept > button.
 - Choose Advanced installation options
 - Click Choose an installation option.
 - Choose the Server installation option.
 - Click the Apply buton.
 - Wait for the installation to be completed. Upon successful installation, click the Close button.
 - Sign your .app file on SignTool: https://www.ssl.com/how-to/automate-ev-code-signing-with-signtool-or-certutil-esigner/#components-of-the-command-line
 
               