Eth2Phone - Send ether to anyone simply by phone number
Blockbutler - Real-time transaction notifications for the blockchain
Cardlet - Rediscover the magic of card giving
Notif.me SDK - A Node.js lib to send all your transactional notifications
Ethereum Live - All the latest updates on Ethereum
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.