In the manifest file for the plugin development, there is a parameter for “homepage_url”.
I know it is optional, but when we use this parameter?
Hi Mo,
As the name, this parameter specifies the URL of homepage based on the user’s local.
Besides that, if you set it, you can set the navigation link icon right after the plug-in name in the plug-in Settings screen as you can see below. 
Like “app index plugin” does not have the icon after that name since this parameter is not set while “Garoon Scheduler Connetor” has it.
The icon will take you to the site you specified for Homepage_url upon clicking.
Hope it helps.
Junko