Flamyngo - Create a city guide with help of your friends.
Sygic Travel Maps - Itinerary planner for independent travelers
Pretty Streets - Discover cities through customized walking itineraries
Detour - Immersive audio walks, now in 17 cities
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.
Heaps - Tinder with your friends. Party in a group.