I have used Toby for Chrome for the past few years to sync my bookmarks across multiple computers without using Chrome's cloud platform. Superdense operates very closely to the free extension but I was willing to pay for it due to the way it combines all my bookmarks into one page and its ability to create its own domain so I can access it with any browser on any computer without having to download an extension. For a tool that is going to be a daily driver, the cost is well worth it and I look forward to future improvements to it (perhaps the ability to save a tab as a bookmark by drag and drop?)