Bluemark is a Chrome extension developed by 가을별 that allows users to access the bookmark feature of mobile Twitter on PC. With this extension, users can conveniently bookmark tweets on Twitter web or TweetDeck, just like they would on their mobile devices.

To use Bluemark, simply install the extension and refresh any open Twitter or TweetDeck tabs. A new "Bookmark Tweet" option will appear in the dropdown menu next to each tweet. In TweetDeck, the option is labeled as "Add to Bookmark." Additionally, clicking on the profile menu at the top will reveal a "Bookmarks [Mobile]" option, which redirects users to the mobile version of the bookmark list page.

It's important to note that the extension may display the "Bookmark Tweet" option even for tweets that have already been bookmarked. This is due to technical limitations in determining whether a tweet has been previously bookmarked. However, this does not significantly impact the overall functionality of the extension.