Twitter’s mobile app for Android and iOS has a night mode which is a dark theme. It is not available for the twitter web app yet. This extension brings the night mode to web. Night mode is enabled by default and it can be switched to the default theme by clicking on the twitter icon that shows up in the tool bar when you visit twitter.com. From version 0.0.4, this extension applies the night mode to theme to all twitter pages.
Read more about it on the dev’s website here
Source: Kodi Addons