Remote Windows Phone App Install
I was just looking for a news aggregation app for Windows Phone on my PC, and I found one called Waze, which was great.
So I was about to whip out my phone and go look for it, but it turns out there was an install button on the website. After clicking it, I was asked to log in to my Microsoft Account, and when I checked my phone a few minutes later, the app was there!
I didn't even know that feature was a thing, but it's pretty cool. My phone wasn't connected to my computer at all, in any way.