Wouldn't it be easier to set your feed to private? Otherwise, people can view your twitter without an account, so even if you had that kind of program, they could still see what you write and it wouldn't be logged.
I really don't think there are any. There aren't any good/legit ones for facebook and twitter doesn't allow for plugins like facebook does. I'd go out on a limb and say any possible twitter thing like what you're looking for would just be some sort of malware.
If you think your privacy is in jeopardy, set your info to private.