Tinder is an online dating app where users can view photos of potential matches in their area and swipe right if interested or left if uninterested. Key features include swiping on profiles, viewing common connections with matches on Facebook, and interacting through "moments" by liking photos. While intended as a dating site, Tinder is often used for casual hookups. It has over 50 million users since launching in 2012, with 1 billion swipes and 12 million matches daily.