Hi,
Sorry for the late reply.
Here is how to do it, from the plugin readme file:
You can add templates via the theme or an add-on plugin. Create a new ‘launcher’ folder in your theme directory, and add your template files there. The new templates will automatically show up on the Settings page of the Launcher plugin. You can also copy templates from the ‘templates’ folder of the plugin into your ‘launcher’ theme folder, but keep in mind that if the file path is the same as that of a default template (e.g. default/default.php), then it will replace the default template instead of adding a new one.
This covers how to add/edit templates via the theme. If you want to include new template via a new plugin, you will need to use the wplauncher_template_paths
filter hook to add the plugin path in the list where the plugin looks for template files.
Hope that helps. If you have any questions, please feel free to ask.