Facebook is enabled now. Yahoo (at least for Calendar integration) is https://launchpad.net/bugs/1554823 GNOME doesn't have a Twitter app in the default install but you could file a bug for Twitter integration, assuming there's some app that would use it.
** Changed in: gnome-online-accounts (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/993531 Title: Compile with Facebook, Twitter and Yahoo providers To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-online-accounts/+bug/993531/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs