Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Event Finda - Find events near you, and all around the world.
Skittish - This is no webinar.
Sporty - Beautiful app for creating/joining sports activities nearby
tophitterpro - the best tennis nearby
Komos - komos.io is a free tool, that helps you discover comedy events near you and get event tickets for your favourite comics.