Trustroots - Travellers community for sharing, hosting and getting people together.
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.
BeWelcome - Open your door to the world!
Sygic Travel Maps - Itinerary planner for independent travelers
Hospitality Club - Free network of people around the world who offer free accommodation, advice and help when they are traveling - hospitality exchange. Free membership.
WorldMate - WorldMate is a travel app that helps individuals plan and organize trips. The app is available for Android and iOS mobile devices, and it is free to download and use.