Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Push for Pizza - The easiest way to order pizza. EVER.
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Facebook Local - Discover places to go and events happening near you
pretix - pretix helps you to sell tickets for your event in an easy way. It supports multi-lingual events and provides a wide range of features
Meetup for iOS and Android - Discover groups that are all about the things you love