Yelp is an online reviews service for local eateries and attractions. Users can leave reviews for any business they've been to, including photos and personal anecdotes. Yelp then gives the establishment a 1-5 star rating based on the total number of user ratings, which makes it easy to find out whether or not a restaurant is worth going to.
Yelp's service can also be found on mobile devices, both as a mobile-friendly Web app and a native client where users can pen in the beginnings of a new review while out and about.
In the past year Yelp has suffered harsh criticisms for its advertising program, which targets businesses that want to improve the way their review pages look. Businesses that pay can remove on-page recommendations for competing restaurants, and select a single user review to go on top of all the others. In response to claims that this was giving businesses a leg up, Yelp recently introduced a way for business owners to publicly respond to user reviews (both good and bad), so that all other users can see.