On a Phone App Called Tinder, Looks Are Everything The quickest hookups in New York these days aren't happening behind the velvet ropes of No. 8, on the bar stools of Dorrian's or in the coed bathroom of the Electric Room. Rather, the action is happening on a new smartphone app, and no, it isn't Grindr. "Anytime I'm at a dinner or an event, social or business, people are buzzing about Tinder," said Erica Berman, 28, an events planner in Manhattan who said that she uses the app several times a day. Ms. Berman is not alone. Technology has hit a new level of shallow, and New York's 20-somethings are embracing it full speed. Introduced to college campuses in September, Tinder taps into the most superficial aspect of the dating scene. After downloading the app and selecting their gender, location and whether they like men or women (or both), users swipe through a stack of profile photos (left for "nope," right for "liked"), based on little more than the person's appearance. If two users "like" each other, they can proceed to have an online conversation. Tinder has been compared to Hot or Not, the once-popular photo rating site, as reimagined in the age of Facebook. Indeed, the app is linked to a user's Facebook account, automatically pulling in a person's profile, photographs and mutual friends. "You don't have to fill out a profile, you don't have to put in info - you just have to like the way someone looks," said Anne Ryan, a 23-year-old project manager in the West Village, who was introduced to Tinder over brunch. Besides, if I don't think someone is hot, or if they don't think I'm pretty, no one ever finds out. Unusual for a dating app, Tinder appeals to men and women, homosexuals and heterosexuals. That was by design. "Irrespective of preference, Tinder solves a basic human need, which is to meet and connect with new people," said Sean Rad, 26, who started Tinder with Justin Mateen, also 26. In the real world, you see someone's face and you decide if you have an attraction to them. In the seven months since Tinder was released to iPhone users, the app has logged 2.4 billion profile ratings and 21 million matches, said Mr. Mateen, a high-tech entrepreneur who lives in Los Angeles. To those who criticize the app for prizing looks over compatibility, Mr. Mateen noted that "approximately 70 percent of those matches have resulted in a two-way conversation." Moreover, he said, the company has received six videos of couples who met on Tinder and are now engaged. Jesse Morris, 25, a handsome marketing executive in Murray Hill, said that he won't be getting engaged anytime soon, but he uses Tinder to cast a wider net. "Bars don't attract everyone, and when you're in a bar, all the best-looking girls are under a magnifying glass from every guy," he said. Because Tinder requires its users to independently indicate interest, you don't need to work through that competition and clutter. Mr. Rad and Mr. Mateen would agree. They aren't just the founders of Tinder, they are users, too. "Justin met the girl he is dating pretty seriously right now on Tinder," Mr. Rad said about his co-founder. He is embarrassed to say the serious part.