ContentMaster is a free Chrome add-on developed by msltoe. It falls under the category of Browsers and is classified as an Add-ons & Tools subcategory. This program allows users to run a content script (javascript) on the page they are browsing. With a simple click on the icon, users can easily edit the content script.

One of the key features of ContentMaster is its ability to run content scripts on web pages, providing users with the flexibility to customize their browsing experience. By default, the content script is undefined, but users can easily update and save the content script by pressing the "update" button.

ContentMaster offers a convenient and user-friendly interface, making it accessible for users of all levels of experience. With its ability to edit content scripts, this add-on provides a valuable tool for users who want to enhance their browsing experience and customize web pages to their liking.