Download Windows Installer
Note: Expresseur is not frequently downloaded or installed. A warning may appear to inform you of a potential risk in installing Expresseur. If you trust Expresseur, proceed with the installation. If not, consider contacting the developer at frevolle@gmail.com to discuss your concerns.
Download the Mac OS X zip app.
The package is buit for Mac OS X versions newer than 10.15 Catalina (for older versions up to 10.11, please contact the developer at frevolle@gmail.com).
After downloading, unzip the file by double-clicking on it, then move the Expresseur app to your Applications folder.
This message appears because the Expresseur.app is not registered in the Mac App Store (100€/year just for one freeware ... ).
If you trust Expresseur, proceed with one of tip hereafter. If not, consider reaching out to the developer at frevolle@gmail.com to address any concerns.
Tutorial video: https://youtu.be/rHYa2XPEXXk?si=fON8JFvQlYXosRAC
How to resolve the problem: "This item is damaged and cannot be opened. You should move this item to the Trash." This can happen when you downloaded an app or game from the internet but not from the Mac App Store. To resolve this issue, run the command: "xattr -cr" followed by the location of your file.
How do I open a damaged app on Mac?
Open the Apple menu > System Preferences. Select Privacy & Security > Developer Tools. Click the (+) button and navigate to the folder where the damaged app is located. Select the app and click Open.
https://support.apple.com/en-us/guide/mac-help/mh40616/mac
Opening a Mac app from an unknown developer
If you try to open an app from an unknown developer and not registered with Apple, a warning dialog box appears. The app has not been reviewed, and macOS cannot verify whether it has been modified or cracked since its release.
The majority of Mac malware infections occur when security settings are bypassed to open an app. It's not recommended to bypass security settings if an app hasn't been verified by Apple, even if it appears to be from a known developer. The safest approach is to search for a version of the app in the Mac App Store or find another equivalent app.
However, if you want, you can still open an app from an unknown developer by manually overriding the Privacy & Security settings.
On your Mac, choose Apple menu > System Settings, then click Privacy & Security in the sidebar. (You may have to scroll down.)
Go to Security, then click Open.
Click Open Anyway.
This button appears for about an hour after you try to open the app.
Enter your password login details, then click OK.
The app is saved as an exception in your security settings, and you can open it later by double-clicking it, just like any other authorized app.
The open-source code for Expresseur is available on GitHub. A GNUmakefile is provided for compilation on the Linux platform, though the compilation hasn't been tested since version 3.4. For assistance, you can reach out to the developer at frevolle@gmail.com.