A user defined custom module can be created only in the developer application.
To create a custom module,
Access the Developer Application.
Click Modules in the left pane.
Click on Add Module. This will open the add New Module form.
Provide the required details in the appropriate fields. For this illustration, a user defined custom module called Inspection is created.
Click Create Module.
A custom module with the given name is created, and you will be redirected to the field builder page of this module. Here, you can configure various fields and sections to gather information from the user.