Having installed the OSDS browser extension, simply visit an HTML document location on the Web, and click the OSDS icon which appears in the address bar, to experience the functionality added to your browser by this extension.
Sample pages you can visit to experience things first hand:
Here are a few screenshots illustrating the effects of OSDS nanotation sniffing (requires OSDS v2.6.1 or later). Click any image to see a full-size screenshot; click the link below the image to see OSDS in action on the same page, in your own browser.
Example (v2.6.1) looking at a comment on a Medium post
Example (v2.6.1) looking at a comment on a Reddit post
Example (v2.6.1) looking at a LinkedIn post
Example (v2.6.1) looking at a comment on a Facebook post
Example (v2.6.1) looking at a comment on a GooglePlus post
Example (v2.2.2) showing JSON-LD based Metadata
Example (v2.2.2) showing HTML5+Microdata based Metadata
Example (v2.2.2) showing RDFa based Metadata