I don't have a twitter account and I'm not going to sign up just to try something out. I don't want to be mean, but the point of a "try it in your web browser" is that the barrier to entry is low. Twitter makes it high again.
I was all ready to sign up as well, I do have a twitter account and I was still put off.
My twitter account is, like my facebook account and my google+ account, private to those whom I know and trust. why would I give that information to some random website?
It's just for authentication because you generate your own ep.io apps (I think that's what it's doing at least). If you look at the requested permissions, you will see that it doesn't need to read or write any of your data.
