If yelping doesn't sound like fun, you may not be as hip as you think. Yelp offers user-generated reviews and information on local businesses and service providers through its website at Yelp.com, and via its mobile app. Its content targets younger, urban consumers and covers restaurants, bars, salons, retailers, doctors, and museums. The site has a social media-friendly interface -- users can create and maintain profiles (complete with friend networks and photos), where they can blog on experiences with businesses. Yelp has established a foothold in cities across the US, Canada, and Europe. The firm was founded in 2004 by former PayPal engineers Jeremy Stoppelman and Russel Simmons. It went public in 2012.