Apigee - Intelligent and complete API platform
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Apiary - Collaborative design, instant API mock, generated documentation, integrated code samples, debugging and automated testing
StatusGator - Monitor all your hosted applications, vendors, and websites, and keep your team informed of outages. StatusGator is the world's premier status aggregator, status page, and website monitoring tool.
Postman - The Collaboration Platform for API Development
WrapAPI - Build an API on top of any website