This Android add-on lets you multitask with your Chromecast
There are already quite a few Chromecast-savvy apps out there, but João Dias' newly completed AutoCast may be one of the most flexible. The Tasker add-on for Android lets you send a wide range of content to Google's media stick in your choice of layout, including multiple things at once -- you can get notifications while you're watching video, or play music while browsing video. You can also create custom home screens that show useful info like battery levels or weather, and it's possible for multiple users to share control over a single Chromecast app, such as an image editor. AutoCast won't address every possible function you might want, but it covers a surprising amount of ground by itself.