You know that Microsoft's HoloLens will do a fair amount on its own, but what can it do in harmony with your PC? Quite a bit, actually. Fans have noticed that Hololens' official companion app for Windows 10 lets you download media, remotely launch apps and even watch a live stream from the augmented reality headset. The app is free to grab if you're curious, although it clearly won't be very useful unless you're willing to plunk down $3,000 for the developer headset -- think of this more as a peek at what you'll get when the eventual mainstream model hits shelves.