In a study conducted by Cambridge University in 2009, Badoo was given the lowest score for privacy among the 45 social networking sites examined.
Tinder is trying to create a different image - it doesn't want to be seen as a "sex satnav." "It's not similar to Badoo in any way," says Mateen.
If you both "like" each other, then you can start messaging and maybe arrange to meet, or take it a step further...
But its co-founder, Justin Mateen, seems reluctant to describe Tinder as a dating app.
Major tech companies including Facebook and Google have signed on to a plan.