I\'m currently running on a Ruby on Rails app with Authlogic handling my authentication and user management.
I\'m struggling to find up to date information on the be
Devise now has built-in OAuth that you can use with Facebook, Github, Twitter, etc. The documentation is quite helpful.
I haven't used it yet, but this one looks promising: http://github.com/viatropos/authlogic-connect
It seems you can handle multiple oauth logins in a single db table, and the example includes keys for facebook, twitter, google etc etc so looks promising on the multiple-applications front
Click on the below link to get the steps for social login.
This is my blog only..
https://rubysolutions.wordpress.com/2014/07/25/facebook-and-google-sign-in-integration-using-devise-and-omniauth-in-rails-4-app-ruby-2/
This looks interesting. Planning to give it a shot.
https://github.com/plataformatec/devise/wiki/Extensions
Edit:
I tried it and I am using devise and omniauth together to handle this:
Check out these links:
http://railscasts.com/episodes/209-introducing-devise
http://railscasts.com/episodes/210-customizing-devise
http://railscasts.com/episodes/235-omniauth-part-1
http://railscasts.com/episodes/236-omniauth-part-2
It is a very good solution