Mind blown! I'll show you how you can use the $10 Duet Display app to turn your Chromebook into an affordable, portable, and useful second monitor for your PC or Mac. One new (to me) trick that I discovered is how I can turn my Chromebook into an external monitor. I've been using a Chromebook as my primary device for the past month or so, and I keep finding new ways to eke out even more productivity from it. The best Chromebooks are generally affordable, well-built, and easy-to-use for general productivity tasks, whether you're a student or you're working from home.