Socket.io - Realtime application framework (Node.JS server)
Send Anywhere - Send whatever you want, wherever you want
Ably - Serious realtime infrastructure
ShareDrop - HTML5 clone of Apple's AirDrop - easy P2P file transfer powered by WebRTC
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.
NitroShare - Official status updates from https://t.co/Uiz47VKYD9. Email updates: https://t.co/zY8kOVT5CN