Chess Time Warnings от Edoardo

Features

This extension adds two types of warning that can be activated and customized as needed

Sound warning

These are played when you reach a given amount of time left. You can activate them for 30,15,10,5,3,2,1 seconds left.

Visual warning

This appears as a border around the chessboard, there's three variants: yellow, orange, red. By default, yellow is under 20 seconds, orange under 8, and red under 3. Those values are also cutomizable.