The Simulator developers call the components an devices created in Simulide "SUBCIRCUITS" and with that name you will find extensive information on this website using its search engine. When you refer to them, always call them Subcircuits, never "models" or another thing.
Here you have info form Simulide:https://www.simulide.com/p/new-subcircuits.htmlhttps://www.simulide.com/p/boards.html
In the "data" folder of Simulide you have many real examples where you can study how they are made.
And if you like to use the subcircuits of my proyects on your own projects follow these steps on the SimulIde "data" folder:
1) Create the "USER" folder and the "USER.xml" file (on simulide/data).
The USER.xml file with the same internal structure as other *.xml, but writing the proper parts of your case...
2) copy my subcircuit folder from the data folder of my project to "USER" folder.
The folder of a subcircuit typically have these three files:
*.sim1 (electrical schematic)
*.package (pinout body)
*_LS.package (Logical Symbol to see and use in your shematic)
3) Add the same "subcircuit name" in USER.xml.
Now the new component will be seen in the SimulIde MENU (Under the USER submenu) ready to use.
There are more things to know about the subject, but what has been said is the basics to start with.
Good luck, it is very very easy!