EventsBase - Find the best professional events nearby or globally
Alkarta - Find happenings in your city.
Rally by Eventbrite - Find the best local events and rally your friends to join
Komos - komos.io is a free tool, that helps you discover comedy events near you and get event tickets for your favourite comics.
Humbler - Find events that support causes you care about
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.