Founder Dimo Trifonov vowed to fight Tinder but said the financial muscle of its parent company, which floated with a value of US$2.9 billion last year, might be too much for it.

“If I’m realistic they can bankrupt us,” said Trifonov. “It’s not about that though, it’s about right or wrong.”

Tinder’s case is understood to be founded on an interview that Trifonov gave with the New York Times saying that the name of the app should be pronounced to rhyme with Tinder.

But Trifonov pointed out that it is pronounced differently in many countries and also questioned Tinder’s right to copyright an existing word, or combination of letters.

“The whole thing is unfair ... can I trademark the word coffee and then sue every coffee shop in the world?” Who does that? Evil corporations do that.”

The web designer, who developed the app after his girlfriend wrote him a love letter about a French woman, said Tinder’s legal assault could force him to fire his eight-strong team.

The threat comes as the app is experiencing a period of growth. The number of would-be troilists using 3nder grew 30 per cent in 2015, sending its revenues soaring by some 980 per cent, while the firm is planning to launch on the Android operating system shortly.

This will allow the app to expand its reach far beyond its current stable of Apple users, because many more people around the world own Android phones.

The growth plan is a turnaround from last year when the company flirted with bankruptcy before securing a US$500,000 investment.

Calling on its users to send pictures of their socks to Tinder, 3nder said: “When a multi-billion corporation is after you, you don’t have many options but to fight back hard or just let them destroy you.

“On the outside Tinder is cute and friendly but if you look below the surface you will see it is one piece of a gigantic corporation hungry for more.”

A spokesperson for Tinder did not respond to requests for comment.