Windows (Custom) Applications monitoring in Nagios



I want to monitor Custom (Windows) Applications (Built on .Net, Java or any other languages) in Nagios XI deployed on any server (Linux, Windows etc…).
How do I achieve this? Are there any plugins available for the same.

I am aware of monitoring Web based applications. I want to monitor Windows/Desktop based applications.
I believe custom apps can be monitored by monitoring specific keywords in the application log files. I want to know if there are any available plugins which do the same.
Please correct me If I am wrong!!!

Any help would be appreciated.