Playing music on your computer is great, but wouldn’t it be cool if you could have that music playing in every room in your house, in sync? Airfoil makes that a possibility. Airfoil 4.0 is an amazing product for anyone who has more than one computer or speaker system connected to an iOS device. The application makes playing music on any speaker in the house dead simple. That alone would be enough to make this application amazing, but it does so much more.

Guitarists have no doubt had some promising apps thus far on the App Store. Apps like AmpliTube for iPhone, PocketAmp, and iShred Live have given us hope for what is possible with guitar processing and amplification emulation. Now, Agile and Peavey have teamed up to produce what I consider the best and most versatile guitar app yet: AmpKit+.

Today is Friday the 13th, but I’m not one to be superstitious. I mean, if today were so bad, would I have such a long list of free apps for you to check out this weekend? Doubtful. There are a bunch of great utilities and limited time freebies to be had. Seriously, you’re going to be happy you clicked through…

Maybe you didn’t think ThinkFlood’s original RedEye IR dock was the best solution for controlling your IR gear. That’s okay, because ThinkFlood listened and is preparing to release the RedEye mini; and like their original IR solution it’s just a bit different from the competition. Instead of using the dock connector and a dongle like everyone else, the RedEye mini uses your iDevice’s headphone jack. Anyone else feeling a little deja vu?

It’s another great week for iDevice apps. But really, what week isn’t? This week it’s all about Siri, your new personal assistant. It will find movie times, make restaurant reservations, and even help you buy tickets for whenever your favorite band is coming to town. And all you have to do is tell it what you want, verbally. But don’t worry, I have more than just Siri inside, including two games free for today only.

This week is brought to you by iTunes Preview. This means that every time you click one of the links on my list, instead of a useless blank page kicking you to iTunes, you’ll first get a snapshot of the app’s page on the App Store right in your browser. A useful feature for sure. Now you can browse these apps at work. Don’t worry, I won’t tell.

The next time you click on a link in my weekly Free Apps Roundup you’ll be pleasantly surprised by an in browser app preview in the tab or window that opens as a result of clicking the App Store link. Instead of a useless blank page, you’ll be able to view a snapshot of what you’ll see on the App Store. And before you say this is uterlly pointless, consider how much more useful this might seem if you aren’t using your normal computer.