This plugin is an example of a properly constructed Jomres plugin that outputs Hello World. It gives you a blueprint for creating your own Jomres plugins.
It is installed through the Jomres Plugin Manager, Third Party Plugins tab.
Once installed it adds menu options to both the frontend and administrator menus of Jomres 9.9+, in the "Misc" menu section in the frontend and in the "Help" section in the administrator area. When clicked, those menu options display Hello World in both the Administrator area and Frontend.
The scripts have plenty of notes, so feel free to dive into the code in /jomres/remote_plugins/hello_world_complete/.