WhosDown - App where you can genuinely make friends—connecting with someone that shares a common interest
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Open Cult - A place for people with common interests to meet IRL.
Zoho Backstage - Plan, run, and analyze your event— all from one place
Speciface - Instant access to contact information of people nearby
Meetup for iOS and Android - Discover groups that are all about the things you love