Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
ATLETO - Connecting everyday athletes
Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.
Sporty - Beautiful app for creating/joining sports activities nearby
SportEasy - SportEasy is an awesome app to communicate with your team and organize your games and practices...
sPortable - instant messaging, video chat and phone calls