It's a dating app, particularly known for setting up one night stands. It uses your location and finds people closest to your proximity, and then it's basically Hot or Not from there. If you match with someone, you can start chatting with them. It's based off an app called "Grindr," which the gays invented to find each other and give each other blowjobs in public restrooms.
In the couple days I've had it, I learned a number of things.
1. I am more shallow than I initially realized
2. I am more racist than I initially realized
3. 1 of every 2 women are in nursing.