Wikivoyage - the free worldwide travel guide that anyone can edit.

Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

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.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

Wikitravel - This article is a Movie/TV Tour.

Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.