FB link to invite fb friends on ES site ?

Hello i'm trying to see if we can get our FB linked users to invite their fb friends to join the site and could not find any such documentation as yet.

Will there be any invite friends from other social media platforms (e.g Facebook / Twitter/ LinkedIn) feature or function released soon or in the pipeline ?

Alternatively Can we do custom invite messages where they can share the link to refer their friends to register on other social media sites ?

thanks !