Yelp Singles
Yelp Singles is to Yelp as Tinder is to Facebook. People already use Yelp for dating, the only challenge is that they don't actually know who's single and who isn't. Let's make this easier. This third party app exists in a future world where you can access more user data through the global API.
Read this Quora answer:
http://www.quora.com/Yelp/What-are-some-surprising-or-interesting-uses-of-Yelp/answer/Steve-Dean-5