RunJS is a free Chrome add-on developed by 孙梦华. It falls under the category of Browsers and is specifically categorized as an Add-ons & Tools. RunJS allows users to automatically execute JavaScript code when a specified webpage finishes loading.

With RunJS, users can streamline their web browsing experience by automating certain tasks or actions that they frequently perform on specific webpages. By simply inputting the desired JavaScript code into the add-on, users can ensure that the code is automatically executed as soon as the designated webpage finishes loading.

This add-on is particularly useful for web developers or individuals who frequently work with JavaScript and want to save time by automating repetitive tasks. RunJS provides a convenient and efficient solution for executing JavaScript code on page load.