Say you're on a Tinder date and the situation turns weird. "You're thinking, I need to get out, I no longer feel safe," says Celine Guedj, a senior at the University of New Hampshire in Durham. She's role-playing the use of a new app, uSafeUS. "That's when you open the app," Guedj explains. One feature called Time to Leave is designed to give you a quick out. "You get a fake call" or text, Guedj says. It sounds like it's your mom or your roommate interrupting you with an urgent request.