TestRail’s web-based test case management is used by thousands of great QA and Development teams to efficiently organize, track and manage software testing.
PractiTest - PractiTest is a cloud based Innovative test management tool.
Postwoman - An online, open source API request builder
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
Postman - The Collaboration Platform for API Development
TestLink - Test & requirements management
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.