twc-history is a Chrome extension developed by kasatomo03 that allows users to save their viewing history on TwitCasting. This extension adds a display of "notwatched" and "watched" to the archive list page on TwitCasting, providing users with a convenient way to keep track of the videos they have watched.

In addition, twc-history adds a toggle switch on video pages, allowing users to specify whether a video is "notwatched" or "watched". The selected status is then saved in Chrome's storage. By default, the status is set as "notwatched". This feature is particularly useful for users who want to keep track of their progress in watching videos on TwitCasting.

With twc-history, users can easily manage and organize their viewing history on TwitCasting, making it a valuable tool for avid TwitCasting users who want to keep track of the videos they have watched.