Kloser is a simple Chrome extension developed by Aleksey Ivashin. As the name suggests, it allows users to quickly close all tabs in the active window and open the default tab. This extension falls under the category of Browsers, specifically Add-ons & Tools.

With Kloser, users have the ability to customize their settings. You can choose your preferred tab that will be opened after using the extension. Additionally, you have the option to configure whether the extension should close pinned tabs or not.

One of the notable features of Kloser is its shortcut - Ctrl + Q. This shortcut makes it even more convenient for users to close all tabs and open the default tab with just a simple key combination.

Overall, Kloser is a handy Chrome extension for those who frequently work with multiple tabs and want a quick way to close them all while opening their preferred tab.