Just like Snapchat and a dozen other social media apps, it's now possible to draw on Periscope. With the latest version of the iOS app, you can long-press on the screen and tap the "Sketch" option to scribble in one of three different colors. For greater control, however, you can also use the dropper tool to pick a custom color from inside your video. It could prove useful if you're streaming and want to point out something in particular, or, if you're bored, simply play some Pictionary with strangers online.