Pusher Beams - Send push notifications programmatically at scale
Ethereum Push Notification Service - Protocol for incentivized, blockchain based notifications.
Truepush - Unleash limitless possibilities with Truepush and save up to $600 monthly. Free up to 10K Subscribers on all features.
Blockbutler - Real-time transaction notifications for the blockchain
F5Bot - F5Bot will send you an email whenever your brand, product, or keyword is mentioned online.
Notif.me SDK - A Node.js lib to send all your transactional notifications