Responsive Viewer - View multiple screen dimensions in one view
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Responsive Website Test - Test any website on desktop, mobile, and tablet
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
LT Browser by Lambdatest - LT Browser is a free dev friendly browser for developers and testers. You can see mobile view of website on different screen sizes and resolution on 50+ pre installed view ports. You can build, test and debug your website faster then ever.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.