I don't think we should even get to the point of optioning "theatre mode". Everyone has cell phones, already. They all have clocks on them. Just don't wear a light-up watch when you go to the theatre, Apple or Samsung or whatever. I'm a technology geek, so I get why people have them (I would like to have one, myself), but I'm smart enough to know not to wear one in a theatre. Or at least to keep it covered with a sleeve (though it's not a reliable option). Take it off and put it in your pocket! Put it back on when you leave the show! GAWD! I often forget how stupid people can be, but it slaps me in the face every time I sit in an audience for a Broadway show or Broadway tour.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian