Fill Screen is a free Chrome add-on developed by Dai Rees that offers a convenient solution for resizing the current window to fill the screen without maximizing it. With just one click, you can change the window size to a non-maximized state that still occupies the full screen space.

The main motivation behind this add-on was to address the issue of the tab-bar in Chrome being located at the very top of the window. This often obstructed access to the tabs, especially when running applications like Winamp in Windowshade mode along the top edge of the desktop. By entering a non-maximized state using Fill Screen, the tabs are pushed down and become easily accessible again.

It's worth mentioning that Fill Screen requires certain permissions to function properly. It needs to run content-scripts in order to access the `window.screen` object, which is not currently exposed through the Chrome Extension API. Additionally, it requires permission to run content-scripts on google.com, as the `activeTab` permission does not apply to the Chrome Start Page under `google.com`.