It doesn't need to be a native code extension; that's not what I'm talking about. In Chrome, you can write browser extensions that are essentially off-screen w

It doesn't need to be a native code extension; that's not what I'm talking about. In Chrome, you can write browser extensions that are essentially off-screen web pages (in simple HTML and JS). Two advantages of "do it in the browser" are, in theory it would run on every platform that browser is installed on with no additional run-time required (like Python or Java), and two, it could run on Chromebooks. Say, in Incognito mode.