Just thought I'd leave a note to anyone having the extension not work, it seems related to the website's language. If your language is anything besides English the extension simply breaks and the buttons fail to show up. I'm not exactly sure how nobody seemed to notice this but that seems to be the reason it's not working for some.
You are correct! Thanks! I rarely use an interface language other than English with twitter and it didn't occur to me that invisible html labels would be localized. Web developers belong in an asylum.
