I just downloaded latest software Montarray for my mac and it says

Get and install the free Go64 application. It will list all 32-bit applications that are incompatible with the strict 64-bit application requirement of Monterey. Then you can contact those third-party developers to see if they offer 64-bit applications stated to be compatible with macOS 12. Same drill for your printer/scanner drivers. If they were not released in 2021, then they likely are not compatible with Monterey, or the vendor may have dropped support for older devices. Also, check the Apple AirPrint list of networkable printers to see if your device is supported. If so, you won't need any vendor drivers to support the device.

You can go to the developer's site for each app and see if it is compatible.

Or upgrade and try the apps. If problem with apps then go to the developer's site.

There is no compilation of which apps work with Monterey.

If the Application is a 32 bit application - the icon in Applications folder would probably have a Bar through the icon denoting it is not compatible with Monterey.