"Fixed elements" (or "sticky" elements) are parts of a web page which stay "fixed" in one place in the window. They're often used to create bars at the top or bottom of the window, making less of the page content visible. This extension adds a button in your browser toolbar you can click to temporarily hide all fixed elements on the page, freeing up more room in the window for you to read the content of the page. (The button is a toggle -- click it again to make those elements show up.)