This page was created for test of saving of localStorage on the domain github.io.
It need for sites which erase it on its own domain (such as google.com, facebook.com etc.).
It have not any script, there is simple static HTML page. saveYourLocalStorage.html have scripts, but userscript Google Search Extra Buttons" not need script on the page because load own script to create PostMessage tunnel (JS). Repository of script from is here.