Howbout - Social calendar app to easily make plans & find availability

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.

tripcake - Doodle for travel plans with friends

Hometown Tourist - Local recommendations to discover the best of the city

eezy - Daily adventures for ambitious people

inviita - inviita is a free app that instantly creates tours that match your mood, in any city in the world.