A new iPhone app is threatening to knock Grindr off its perch as the number one app for gay men.

Kroozr claims to use smartphone technology to determine whether men in the user’s vicinity are gay and can even filter out undesirables, such as those wearing sandals with socks.

According to creator Peter Kelly, the app takes the guesswork out of gaydar, cuts down on valuable ‘sussing out’ time and weeds out weirdos.

All users need to do is turn on their smartphone and wait for Kroozr to assess nearby men with its inbuilt Kinsey Scale.

Mr Kelly said: “Kroozr is the new future of gay dating that will turn every trip to M&S, every queue for the cashpoint, every Boris bike trip into a hot party full of your type of guy.

“Just fill in the details of your ideal man, turn on the app and go about your business. When you get within eyeshot of a hot guy, you can check him out on Kroozr.”

He added: “We’ve even developed a ‘filtering’ feature, whereby you can set the app to screen out men with ponytails, bumbags or Chinese symbol tattoos.

“There’ll be no more turning up expecting Rob Lowe and getting Bob Crow.”