Blockbutler - Real-time transaction notifications for the blockchain
Facebook Local - Discover places to go and events happening near you
Notif.me SDK - A Node.js lib to send all your transactional notifications
TechEvents.co - Tech and startup events aggregator
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets