That looks really cool, I would absolutely use this if I was using Twitter. One question: Do you cut the text after precisely 280 chars and then fit the rest in to the next tweet, or did you implement a "smarter" solution (like cutting it at the last space and adding "1/4" to indicate the length of the thread or adding an ellipsis or whatever)?
It cuts after 280 chars if no other possibility. It tries to search for a \n or a "." in this 280 chars to have a cut at the end of sentence and make the cut less ugly.