How To Use Tinder, A Socially Acceptable Way To Call Someone Ugly Or Attractive That's Worth $500 Million

Tinder is a year-old mobile dating app that was recently valued by investors at $500 million.

It works a lot like Hot or Not, allowing users to quickly judge each others' looks based on profile pictures. If both people find each other attractive, Tinder allows them to "match," then message back and forth to schedule a date.

The Los Angeles-based startup was founded by four entrepreneurs Sean Rad, Justin Mateen, Jonathan Badeen, and Christopher Gulczynski, and it is backed by IAC, the parent company of Match and OKCupid.

In February Tinder was generating 10 million matches per day.

Here's how the $500 million dating sensation works.