Yelp received an update today, and it adds a brand-new mobile-exclusive feature called Deals, which is essentially a competitor to Groupon's Groupon Now!. The Deals button found on the updated app integrates Yelp Special Offers, Check-In Offers, and its time/location-sensitive Deals all into a single, location-based menu.
Like Groupon Now!, you can only view offers within a certain distance of your current location (which is to say, it can't be manually set). The fact that it puts together all of Yelp's discount systems into a single list is really pretty handy, but unfortunately, there's no option to filter or sort the results.
You can get the updated app from the Market now.