Using an AI method known as natural language processing, the 'flirt detector' has been trained on millions of creepy messages and pick-up lines circulating the internet, including a huge number submitted to Reddit (of course). It also responds to the behavioral activity of the user: who they message, how often, whether it's a copy/paste job or if they've bothered to think of something original, and so on.

All of this combines into what Patook's founders unsettlingly call a 'magic sauce', which determines whether a message is sent or not. "What kind of music do you like?" is fine. "Would you like to sit on my face?" is not. Break the rules, and you're banned. In fact, upon the app's beta release in 2016, five percent of users were banned before their first message was even delivered.

According to Patook CEO Antoine El Daher: "Initial feedback to the app has been extraordinary. People seeking friends and not romantic relationships have been left out in the cold until now. We anticipate rapid growth among all genders, and so far have seen approximately 40% women, 40% men, and 20% joining as couples."

Romantic advances aside, Patook (which means 'little hug' in Armenian) operates in much the same way as a dating app. There's an extensive set of privacy controls, and users build a profile and search for friends based on the usual criteria: location, interests, age range. The app also uses a points system to specifically identify and rate the value of the criteria they want in a friend. So if you're into hiking, you might give five points to people who list 'the great outdoors' as an interest, or if you're into Napalm Death, you might give points to other metalheads. Whatever floats your boat, as long as you keep it clean.