Other than display what I type, I couldn't reckon anything else this can do. Reading the comments I see I missed some things but that's a pretty clear failure

Other than display what I type, I couldn't reckon anything else this can do. Reading the comments I see I missed some things but that's a pretty clear failure of UI design. So I went back. Still can't see any features other than display what I type. So I try again, this time on Chrome. Now I hear very annoying audio as I type, and no hint of any other features. How the hell does this POC make it to the front page of Hacker News?