Trustroots - Travellers community for sharing, hosting and getting people together.
GetYourGuide - Get tickets to the most popular attractions while travelling
BeWelcome - Open your door to the world!
Klook - Discover & book amazing experiences at exclusive prices
Hospitality Club - Free network of people around the world who offer free accommodation, advice and help when they are traveling - hospitality exchange. Free membership.
Airbnb - Book unique places to stay and things to do.