Yelp has released an update to its social location app for the iPhone and iPod touch adding a new Check-in Offers feature. Yelp allows users to search for nearby businesses such as restaurants, bars and cafes using iOS Location Services, browse through reviews by other users and add their own quick tips, photos and reviews right from their iPhone. Yelp 4.5 adds a new Check-In Offers feature that allows users to take advantage of discounts and specials…