IRC Inspired Theme for Facebook Messenger is a free Chrome add-on developed by iFallUpHill Studios. This add-on provides a flat, IRC-inspired theme for the Facebook Messenger Web App. With this theme, users can enjoy a dark and minimalistic interface for their Messenger conversations.

Upon installation, users can simply click on the square icon labeled "IRC" in the top left corner of Messenger to enable the theme. Once enabled, the add-on brings several changes to the Messenger interface. It moves all messages to the left-hand side of the screen, modifies image previews to be less intrusive, and ensures a smoother flow of conversations in the feed.

One of the key features of IRC Inspired Theme for Facebook Messenger is its ability to retain all the functionality of Messenger while providing a visually appealing theme. Additionally, it offers a second "IRC" mode for users who prefer an even more minimalist experience. To enable this mode, users can simply use the keyboard combination of Cmd/Ctrl + Click on the IRC button.

Overall, IRC Inspired Theme for Facebook Messenger is a great add-on for users who want to enhance their Messenger experience with a clean and minimalistic theme. It is easy to install and provides a refreshing change to the default Messenger interface.