Hey Everyone,
Just wanted to jump in here and say that me and my business partner are making a bookmarking app that falls in squarely in the visual and private corner of all these apps if you look at the article.
It's called Linkship and you can check it out at https://www.getlinkship.com
It's in the very early stages of development, and we're in the process of adding a whole slew of useful features. Would love for anyone to try it out and give us feedback. We're only two people, but we're working hard to do this right :D