Tab-bulk-closer

This browser from Chrome and Firefox helps manages tabs by allowing automatic categorization and bulk tab closing of tabs.

Installing

Firefox:

Copy firefox/manifest.json to manifest.json.
Go to about:debugging
Click on "This Firefox"
Click on "Load Temporary Add-On"
Open manifest.json.

Chrome:

Copy chrome/manifest.json to manifest.json.
Go to chrome://extensions
Click on "Load unpacked extension"
Open the folder containing manifest.json.