Not many javascript stuff comes to mind, but you might find more implementations if you search for a specific problem you were trying to solve. The closing javascript thing that comes to mind is the letmegooglethatforyou site, an extreme way to point out the search button.....

From a personal point of view, Sometimes I would just email myself a link to a webpage if I wanted to view it later on mobile or vice versa.

In technical support over email, I used to send customers a link to a kb article or a pdf and a page number. I never had to go beyond something along the lines of, here is a link, you forgot to do step 4 or follow the instructions under the known resolution section.

From a bug reporting point of view, Most people would send a picture and send the dropbox link over slack/email. Dropbox has a little popup with the link to the image after taking a screenshot so it is very easy and fast.

It reminds me of Onenote and Evernote feature to copy snippets from a webpage, though I never tried to share the content.

While not directly similar, The code for searching for specific parts of a webpage seems similar to some web scraping solutions. Ie, here is a webpage, I want to scrape this selection for all similar pages,etc.