Clever Apps: Airfoil 

Rogue Amoeba's Airfoil is one of those apps that you don't really need, but once you have it, you wonder how you ever lived without it.

The premise is reasonably simple: you've got audio on your desktop computer, you want to listen to it somewhere else. For example, you're running Spotify and want to listen to it as you clean around the house. Unless you're paying for Spotify Premium, there's no way to get the music out of Spotify onto your stereo short of plugging the audio of your computer into your stereo.

With Airfoil, you gain a bunch of options. When you run Airfoil, you can send the audio to any Apple TV you've got. You can send the audio to any device running the free Airfoil Speakers application -- another desktop, a laptop in another room, or even your iPhone.

Pretty awesome.

But, for me, the coolest thing with Airfoil happened the other day. I was watching some TV off of our iMac, and was trying to be polite and keep the sound low.

"Self," I thought, "why not use Airfoil and broadcast the sound to your iPhone."

Brilliant. Except, the sound was a couple of seconds behind the video. Which was incredibly annoying.

The smart folks at Rogue Amoeba have it covered, though. Turns out, the Airplay format inserts a 2 second delay. But, if you run the Airfoil Video Player, it will delay the video 2 seconds, so the sound and video are in sync. Including for web videos. So, I laid back and watched some TV off of Hulu, while listening to the sound as it played through my iPhone.

For $25, I continually find uses for Airfoil. It's easily worth it (and it works for PCs too).