[Plugin: Facebook Registration Tool] multisite related question

this plugin’s FAQ sounded great:

Does this work with multisite?
Yes! As of version 0.3, this plugin works with multisite!

but I need to know how to activate it: only on the main site or network wide? I think only the main site will do but want to make sure.

besides, everyone is complaining that the plugin is broken, whats the actual story, not even the demo is working ??

https://www.ads-software.com/extend/plugins/facebook-registration-tool/