London-based startup 3nder — the name can be pronounced "Thrinder" to rhyme with "Tinder," according to its founder — said it has raised $500,000 in seed capital from a pair of unnamed angel investors.

Since 3nder's mid-2014 launch, nearly 1 million users have downloaded the iOS app in search of kinky hookups — whether "straight, bisexual, gay, poly- or pansexual," says founder and CEO Dimo Trifonov.

The torrid growth has spilled into the US, where New York is 3nder's second-biggest market behind California. Worldwide, users are sending about 1.2 million messages a month on 3nder while logging
around 4 million swipes.