A device to warn autistic people when they’re annoying or boring others could do a great deal of good in the world. (Imagine if Larry Summers had owned one.)
But I’m less excited by the potential benefits than I am dazzled by the idea that a piece of software that runs on a computer small enough to fit in your pocket can be taught to recognize the symptoms of boredom or annoyance, as well as other emotions not expressed by a simple facial expression. The implications for social-psych and anthropology research, to say nothing of marketing studies, should be profound.
Footnote I won’t defend my appetite for science fiction on literary grounds, But one advantage of having spent a good chunk of one’s adolescence reading sci-fi is that you expect rapid technological change. Even against that backdrop, though, this seems like a remarkable feat of techno-wizardry.