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.
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Mixpanel - Mixpanel is the most advanced analytics platform in the world for mobile & web.
WrapAPI - Build an API on top of any website
Pushy - Pushy is a reliable push notification gateway for time-sensitive, mission-critical apps.
Apinizer - Create, Secure and Publish your API in 21 seconds