Responsive Design Tester is a free Chrome add-on developed by Miqdad Ali K. It falls under the category of Browsers and specifically belongs to the Add-ons & Tools subcategory. This handy tool allows users to test the responsiveness of their websites.

With Responsive Design Tester, users can easily evaluate how their websites appear and function on different screen sizes and resolutions. This is especially useful in today's mobile-driven world, where optimizing websites for various devices is crucial.

The plugin is inspired by the popular "Mobile Responsive Web Design Tester" available on the Chrome Web Store. It provides a simple and intuitive interface for users to select specific device types or input custom dimensions for testing. By simulating different screen sizes, users can identify any design flaws or responsiveness issues that need to be addressed.

Please note that there are currently two reported issues with this plugin, specifically related to Chrome crashes. It is recommended to proceed with caution and ensure that your Chrome browser is up to date before using Responsive Design Tester.

Overall, Responsive Design Tester is a valuable tool for web developers and designers who want to ensure that their websites are responsive across different devices and screen sizes.