OneSignal - Customer engagement platform used by over 1 million developers and marketers; the fastest and most reliable way to send mobile and web push notifications, in-app messages, emails, and SMS.
usql - Universal command-line interface for SQL databases
Truepush - Unleash limitless possibilities with Truepush and save up to $600 monthly. Free up to 10K Subscribers on all features.
Jugglingdb - Multi-database ORM for nodejs: redis, mongodb, mysql, sqlite3, postgresql, arango, in-memory... - 1602/jugglingdb
PushCrew - Push Notifications for Websites
Rollbar - Rollbar collects errors that happen in your application, notifies you, and analyzes them so you can debug and fix them. Ruby, Python, PHP, Node.js, JavaScript, and Flash libraries available.