Visual Studio Team Services - Visual Studio Team Services (VSTS) provides unlimited Git hosting, cloud build for CI, agile planning and continuous delivery.
Postman - The Collaboration Platform for API Development
Helix ALM - Helix ALM is the single, integrated application that lets you centralize and manage requirements, test cases, issues, and other development artifacts and their relationships.
Postwoman - An online, open source API request builder
Jama Connect - The Leader in Requirements Management Solutions
Selenium - Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily, it is for automating web applications for testing purposes, but is certainly not limited to just that.