This plugin comes with 2 installable plugins - SSO Server and SSO Client that needs to be installed ...
There is no limit on adding Client sites, so you can add any number of Client sites to 1 Server site...
You can use this plugin only on 1 Server site. If you want to use this plugin more than 1 Server sit...
When you enable signup from Server site to Client site, then you also need to map the Profile fields...