Stumble Across is a Chrome add-on developed by StumbleAcross. It falls under the category of Browsers and the subcategory of Add-ons & Tools. This free program allows users to bookmark webpages on the blockchain, ensuring their permanence and security.

With Stumble Across, users can easily bookmark interesting webpages, ensuring that they will be accessible forever. Additionally, users can click the "Stumble" button to discover random webpages that have been bookmarked by other users. This feature adds an element of serendipity and discovery to the browsing experience.

One unique aspect of Stumble Across is that users can earn bitcoin when other users like their bookmarked content. This incentivizes the sharing of high-quality and interesting webpages.

Please note that Stumble Across is currently in beta version, so there may be some room for improvement. The developer welcomes suggestions for enhancements to the program.

To start using Stumble Across, simply install the Chrome add-on. After installation, you may need to pin the extension to your browser, as shown in the second screenshot provided.