Swarm - Swarm lets you earn prizes and compete with friends based on the places you go.
Foursquare - Foursquare is all about helping you find new ways to explore your city.
Yelp - The free Yelp mobile app is the fastest and easiest way to search for businesses near you. Download it now to get started.
Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.
Mapstr - Your places, your world!
TripIt - TripIt is a travel app that creates a master itinerary to organize all of your plans for your vacation or work trip in one spot.