Nowadays, telling someone that you’ve started using a dating app is hardly an unusual thing to say. Unless it’s to your new husband.

I signed up to the dating app Bumble, which, like other apps such as Tinder, OKCupid, Hinge and Happn, offer a route to romance. But I’m using Bumble’s BFF mode, a new setting launched in March for women looking to make platonic friends. Just as singles swipe right to indicate they’re interested in going on a romantic date with someone, women on BFF can now swipe right for the platonic equivalent.

Just as singles swipe right to go on a romantic date, women on BFF can now swipe right for the platonic equivalent

In fact a host of new apps aimed at making friends have launched in recent months. Hey VINA!, an app for women seeking platonic friendships, launched in January, while Patook, which launched in April, allows you to assign points to specific traits you’re looking for in potential friends. Even Tinder is testing a new friend-making setting called Tinder Social with a group of users in Australia.

But will they work? I decided to find out for myself. I also set out to discover what science has to say about friendship in the 21st Century – how it shapes our happiness, for example – and whether technology might be changing that.

After three days of swiping right on about 20 women between the ages of 26 and 39 located within 100 miles (161km) from me in Tel Aviv, I still had no matches, and started to get nervous. “Why doesn’t anyone want to be friends with me?” I wondered to anyone who would listen, while analysing my profile for flaws.

When I finally got a match, with a 26-year-old woman named Tal who studied at the same university as me, I was excited and then immediately stumped. I met my husband several years ago, before dating apps were the norm. Adding to the pressure is the fact that Bumble requires users to start a chat with a match within 24 hours, or else the match disappears.

“What do I say?” I asked my real life friend Debra, “Should I tell her I’m working on a story right off the bat? Should I invite her to meet for a drink? I don’t want to come on too strong.”

“Can you just say hi?” Debra suggested, rather unhelpfully.

Friendship and wellbeing

Research suggests quality relationships with friends are correlated to increased wellbeing, especially in cultures that emphasise individuality, like in the UK and America. Friendship is a major predictor of happiness, says Meliksah Demir, a psychology professor at Northern Arizona University who edited Friendship and Happiness, Across the Life-Span and Cultures. “In every age group, friendship quality, friendship satisfaction, intimacy and support are all positively correlated with individual happiness,” he says.  “This is the case even when you control for personality types, like extraversion and agreeableness, which are also correlated with friendship.”

People with larger friend networks have a higher pain tolerance

Friends act as companions, validate our beliefs about ourselves, support our autonomy, make us feel competent and as if we matter to other people, and provide other basic psychological needs. They may even make us more physically robust. A study published in April suggests that people with larger friend networks also have a higher pain tolerance.

“Friendship and friendship quality are also negatively related to loneliness, depression and anxiety in general,” says Demir, “For every wellbeing outcome investigated, in addition to happiness, friends make a positive difference.”

While both the quantity and quality of friends are associated with increased happiness, experts say having a few high quality relationships is better than having a lot of not-so-close companions.

A theory proposed by Robin Dunbar, an evolutionary psychologist at the University of Oxford, suggests that we have an upper limit to the amount of stable relationships we are capable of maintaining in our broader social network. “Dunbar’s Number” is around 150, even with the aid of social media. A study on Twitter behaviour suggests we only actively interact with 100 to 200 other users.

The good news is that research indicates most people are satisfied with the number of friends they have, with a 2004 Gallup poll indicating that Americans have about nine close friends on average. Research from 2010 also shows that between 2002 and 2007, the number of friendships increased, which was particularly true for heavy internet users.

Unfortunately, this may not ring true for everyone. According to a recent survey by Relate, a relationship-focused charity in the UK, almost one in 10 people in the UK say they have no close friends at all.

And maintaining friendships may get harder as we get older. A meta-analysis from 2013 indicates that our global social networks tend to increase up until young adulthood and then decrease as we continue to age. This makes sense, since marriage and kids take up a lot of our resources and priorities. One study from 2015, for example, indicated that marriage typically costs people two friends.

Marriage typically costs people two friends

Furthermore, as adults become increasingly mobile – with the number of expats growing in recent years and expected to continue to increase – more of us may find ourselves living in new cities and countries around the world, and farther away from our friends. So while technology may help us maintain our relationships with long-distance friends, we might find ourselves with fewer friends and acquaintances in our daily lives.

Has the way we make friends changed then? In Victorian England, upper classes made friends primarily through private schools, universities, professions and institutions, like political clubs that were founded in the 18th Century. “Friendships (were) largely restricted to such circles,” says Brian Young, a history professor, also at Oxford. “Acquaintances rather than 'friends' tended to be recruited outside such charmed circles.” Intimate friendships rarely exceeded 10 or 12 people, according to Young.

Using a more scientific approach, researchers in the 1950s backed up the idea that proximity and repeated contact – like what students experience in a university setting for example, are crucial to the formation of friendships, says Demir. For example, a well-known study of student dorms at MIT by social psychologist Leon Festinger, illustrated the importance of proximity, even within the same building. In that study, students indicated their next-door neighbour was a close companion 41% of the time, which dropped to 22% for people living two doors away and 16% for people living three doors away.

More recently, studies have examined the importance of social media friends – like those on Facebook – to our wellbeing. A large-scale study in Canada comparing online and offline friendships found that offline friendships were far more important to subjective wellbeing than online friendships, especially for single people. While the number of online friendships was unrelated to wellbeing, doubling the amount of offline friendships was the wellbeing equivalent to a 50% increase in income.

Doubling the amount of offline friendships was the wellbeing equivalent to a 50% increase in income

And while Facebook and other social media sites can help us keep in touch with people and strengthen offline friendships, it’s also clear that Facebook friends don’t necessarily translate into real friends. A recent study by Dunbar indicated that only about four of our Facebook friends are considered part of our “sympathy clique,” or people we rely on in times of distress, while about 14 could be considered close friends.

Which is where apps like Bumble BFF hope to be different. Messaging someone through an app may feel uncomfortable, but it’s only meant to be a medium for making friends in real life, and rather quickly. After only a few messages over the course of a couple of hours, I’m prepared to ask Tal if she wants to meet for a drink. But she beat me to it.

A few days later, we meet for a glass of wine and chat about our lives. I discover Tal is finishing her degree in social work. After her core group of friends in the city moved away for jobs or relationships, she found she didn’t have a large social network nearby and thought it could be interesting to try making new ones with Bumble BFF.

While there are obvious safety concerns for people meeting up with unverified “friends” in real life, it is becoming more widespread. Research has shown that teens are already adept at turning online friendships into real life friends, with one in three British teenagers meeting a social network friend in real life. And it’s already clear that more people in their 20s and 30s, at least in Tel Aviv, are using BFF Bumble. I’ve had five more matches since Tal and more women seem to be joining all the time.

Unless I have serious chemistry with someone over text, I probably won’t meet anyone in real life. But I could certainly see myself using the app more if I moved to a new city and didn’t already have a social network in place.

Will Tal and I ever meet again? Who knows. After our date we hugged goodbye and promised, rather ambiguously, to “be in touch”.

Join 600,000+ Future fans by liking us on Facebook, or follow us on Twitter, Google+, LinkedIn and Instagram

If you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, Travel and Autos, delivered to your inbox every Friday.