Google has made another update to the Slides app. It's one offshoot of the Chromecast idea that has brought casting more mainstream and more useful. The Chromecast isn't just a single dongle that lets you stream images and videos to a TV display. It's now being used when giving important presentations at work or in school. Mirroring is one easy way to "cast" but a dedicated app like the Slides will make the job easier and more convenient.