What does "Sign in with Twitter to contribute" mean? Does that mean I get to contribute to the discussion by posting a reply if I sign in with Twitter? That's what "contribute" means to me, but it seems unlikely, especially given the relative paucity of posts in this discussion.

I wouldn't bother making a comment here to ask; normally I would just sign in and see for myself. But this app wants permission to make posts to my Twitter account, and I never, ever do that. (I hate it when I sign up for something and I later find a post in my timeline that says "A-hyuk hyuk, I just joined SomeSkeezyWebsite and I'm having a blast, LOL!")