Many thanks for this plugin.
Created twitter application
Set Access level to Read & Write
Created Access Token
Inputed Access token into Twitter API Token
Inputed Access token secret into Twitter API Secret
No users found for the Twitter extension.
Then in Open Educational Resources---->Accounts---->Twitter ----->Start Authorisation -------> Failed to validate oauth signature and token
Obviously I'm doing something wrong as Boone says it works - so it must!!
also can linkedin and Facebook settings be far away !