Singles who believe in love at first sight can turn to new apps that will match them with potential dates in time for Valentine’s Day, but only if each person has expressed an interest.

With the new dating apps, users simply flip through photos of people in nearby locations and express their interest in dating someone. If there’s a mutual attraction, the app connects them for a conversation. If not, their feelings remain anonymous.

“It limits the conversations to people you’ve actually expressed an interest in. So each of those conversations starts at a very deep level,” said Sean Rad, co-founder and CEO of Los Angeles-based company Tinder, which developed the app of the same name.

Makers of the Tinder app, which is available worldwide for iPhone, said it has matched more than 10 million couples since it was launched in September.

The app pulls in member photos of people from Facebook, and then it’s as simple as anonymously indicating interest in that person. If both people like each other, messages can be sent between the two users.

Rad said most users are between 18 and 30 years old.

Let’s Date, which was released across the United States last week for the iPhone, is a similar app. But rather than simply focusing on the photo, the app provides the person’s interests from Facebook for a broader view of the potential date.

“Our goal was to create an app that replicated the real world experience of going to a party or bar full of potentially eligible people,” said Sean Suhl, founder of Let’s Date.

“You’re put into a crowd of people and if someone catches your eye and they catch your eye, then a conversation is struck up and then someone might ask the other person out on a date,” he added.

The app resulted from a frustration with other dating apps, according to Suhl, who described them as “artificial and laborious”.