A three-finger swipe will stream to Apple TV, or any AirPlay-capable speaker or receiver, without a third-party app.
Funny thing about standards — there are so many of them that you've got a pretty good chance your device supports at least one. But when it comes to Apple's AirPlay, Android devices haven't been invited to play. At least not out of the box. Third-party apps can get the job done, but there's something to be said for a phone supporting standards natively.
That's a big deal for a few reasons. One is that supporting more standards is almost always better. (Not to be confused with there being too many standards in the first place.) If you live or work around someone who uses an iOS device, this puts you on the same playing field, at least in that regard.
The other is that AirPlay is baked into all sorts of things. Apple TV is the obvious one, of course. With it you can push apps and displays from iOS and OSX devices (as in Macs and iPhones and iPads) to a television a lot like we can with Chromecast and Android. But loads of stereo receivers and speakers support AirPlay, too. (Again, just as more are starting to support the Cast protocol natively.)
HTC Connect — which you activate by swiping three fingers up on the display — is one of those criminally underrated features on HTC's past few phones. It's a great thing to have. And with the addition of AirPlay it's only getting better.