Blockbutler - Real-time transaction notifications for the blockchain
Ethereum Live - All the latest updates on Ethereum
CryptoNotify - Receive transaction notifications of any BTC or ETH address
Ethereum - Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
Notif.me SDK - A Node.js lib to send all your transactional notifications
Pragma - The home base for Ethereum developers.