Using this tool you can invite all FB friends to join a group or invite a Friend to join all groups joined by you.
This software is neither created nor endorsed by Facebook.
Privacy notice: This software neither collects nor transmits any personally identifiable information. This software does not track your browsing behaviour. Information necessary for functioning of this software is stored on the devices of end user, our servers do not have access to this information. All information required for functioning of this software is kept between end-user and Facebook servers.
Terms of service: https://www.gethappysoftware.com/tos/
This software will help you to invite your friends to join a group.
(1) Invite multiple Facebook friends to join a Facebook group: This feature will allow you to invite multiple Facebook friends to join a Facebook group.
(2) Invite a Facebook friend to join multiple groups joined by you: This feature will allow you to invite a Facebook friend to join multiple Facebook groups joined by you.