Pragma - The home base for Ethereum developers.
Blockbutler - Real-time transaction notifications for the blockchain
Telnyx SMS API - Build global text messaging right in your app
CryptoNotify - Receive transaction notifications of any BTC or ETH address
Wit.ai - Easily create text or voice based bots that humans can chat with on their preferred messaging...
Pusher Beams - Send push notifications programmatically at scale