Remember the Jim Carrey/Kate Winslet movie “Eternal Sunshine of the Spotless Mind”? How many times have we all wished we could totally erase our exes, right? Well, thanks to the app Killswitch, you actually can, at least virtually. Killswitch does all the annoying ex-erasing work for you. Users simply pick the offending ex from their Facebook friends list, and Killswitch does the rest — untagging them from photos and removing all mention of them from your status updates forever. Or until you get back together — whichever comes first.