The hack is basically a bridge b/w chrome devtools and localhost editing. A web developer spends much time on devtools (if he uses chrome). Each time, he tries some changes on the site, replicates them to files on the localhost, and then again has to switch back to the browser and do refresh. The hack tries to make that cycle simpler. You do your edits on devtools, once you are ready, push a button (will try to make it a keyboard shortcut) and the changes will go back to the localhost files (js and css changes) and site itself will be refreshed. If one edits the localhost file, again the page on the browser is refreshed (just Alt+Tab to it).