This is Crumb Log, a sourdough log somebody built in a conversation. It is here for its timer: start the bulk ferment, close the page, come back later and it still has the right time left, then it chimes at zero. That is the same timer you would get, wrapped around whatever you are actually timing.
Everything you make runs in a locked-down sandbox with a strict content security policy. It cannot reach your accounts, your files, or anything else you have made.