Sidebar Toggle is a free Chrome add-on developed by sinanm89. This add-on is designed to hide sidebars on popular websites such as Reddit, Wikipedia, Facebook, and Youtube, allowing users to save screen estate. The add-on provides a convenient toggle feature that can be accessed by clicking on the icon or using the keyboard shortcut Command/Ctrl+Shift+E.

One of the main features of Sidebar Toggle is its ability to clear arbitrary spaces on pages that are constantly open on the user's screen. Currently, the add-on supports popular websites like Reddit, Wikipedia, Youtube, and Facebook. The developer also offers the option to add more sites on demand, providing flexibility for users with specific needs.

It is worth noting that due to the nature of Wikipedia pages being hosted on various sites, the add-on requires permission to allow for all pages. However, the developer clarifies that the add-on only removes some CSS elements and does not perform any other actions.

Overall, Sidebar Toggle is a useful Chrome add-on for users who want to maximize their screen space by hiding sidebars on popular websites.