Of all the online era services, Tinder is probably the most divisive.
If you're single and under 40, you have almost certainly used it. If you're married or in a relationship, you may never have seen it. But don't underestimate its prevalence. Over 200,000 Irish people have a Tinder account, with almost 50,000 using it every single day, according to Ipsos MRBI.
The basic principle with Tinder is simple. Tell the app what kind of person (gender, age range) you're interested in meeting and it starts showing you people nearby. Swipe right if you like the look of them, swipe left if you don't. If a person you like swipes right for you too, the app connects you and you can chat or arrange to meet up.
If this sounds superficial, it is. It's largely based on looks and little else.
Because it starts out as a remote correspondence with a stranger, things come to a head quickly.
There are fewer inhibitions and people are more direct about what they're looking for.
Walk into any city bar on a Saturday night and you'll see twentysomethings sitting there, swiping on their phone screens. They're not watching the 'Ray D'Arcy Show'.
It's not just grown-ups. Previous research from Ipsos MRBI has shown that one in six teenagers over 15 also uses the service.
There are some notional safeguards built in. To sign up, you have to use a Facebook account or a phone number, meaning you don't have total anonymity. So if someone really wants to find out more about the person they're connecting to, they may try searching in Facebook for the name and photo they see on Tinder.
Aside from that, it's a pretty unguarded, laissez-faire environment.
Critics of Tinder say it is contributing to a generation which regards relationships as on-demand services to be ordered by swiping an app.
This is countered by those who argue that Tinder has given shy people, who struggle to make an impression in bars or who are geographically isolated, access to relationship opportunities.
Both arguments have merit. I know of one Dublin couple who are now married after first meeting through Tinder.
Like it or loathe it, there is no question that services like this are here to stay.