Not familiar with any of the applications you listed, but the genera process of developing a monitoring standard for custom applications involves breaking down the individual tiers (database, app, web, etc) of the custom application and monitor those dependencies. And then spend some time in an IDE (for SQL, PowerShell, Python, or Perl) to fetch any application-specific metrics.
For instance, we have an app developed at the company I work for that uses SQL Server and IIS. So I deploy those monitoring templates to capture performance metrics. The app requires specific Windows processes to be running, so I cobble together a template that monitors those specific processes. Lastly this app exposes data on the number of transactions processed via REST API, so I quickly slap together a PowerShell monitor to do those REST calls.
SAM supports whatever scripting languages that are packaged with or can be installed on the servers you want to monitor and PowerShell.