First Automatic friends plugin for Jomsocial . It can process confirmed friendships or Friendship requests with default or custom message . It can friend from one or more users, and also every users. It processes for each new registered user, registering from the front or backend.
When processing automatic friends requests, you can use the term {target} in the custom message so it is replaced by the new user name or username according to the Jomsocial global setting.