BMATBMAT (short for BookMarks App Thing; yeah, I'm original) is a web application that allows you to manage your bookmarks across multiple devices. I made it because I was fed up with all the existing ones on the market because they lacked features I wanted. Specifically, tag implication and search. If you want to try it, you can make a trial account which lasts for a day or two.
You can view and use the application at bmat.savagewolf.org.