The Alternative Greek Keyboard Layouts is a free Chrome extension developed by freshp. It adds three alternative keyboard layouts for the Greek language on ChromeOS. The available layouts include monotonic Dvorak, polytonic, and polytonic Dvorak. This extension is specifically designed for ChromeOS and works only on this platform.

To install the extension, simply follow the instructions provided. First, open Chrome OS Settings from the system tray in the bottom right corner. Then, click on "Advanced" to expand the advanced settings. Next, click on "Languages and inputs". If you haven't added Greek as a language already, follow the steps to add it. Once Greek is added, click on "Inputs" and then click the "+ Add input methods" button. Type "Greek" in the dialog box and select the desired layout(s) from the options provided. Finally, click the "Add" button to complete the installation.

With the Alternative Greek Keyboard Layouts extension installed, users can easily switch between different keyboard layouts by pressing Ctrl+Shift+Space or using the button in the system tray. The latest version, v3.0.0, includes bug fixes for displaying breathing marks on rho and upper case omega.

Please note that this extension is only compatible with ChromeOS and may not work on other platforms.