Usually I don’t use my blog to promote, or even mention, good Mac (or App Store) apps. But this app (which has versions for both platforms, and more) I think needs to be given an entry dedicated to it on my blog.

SimplifyMedia is a Mac, Windows, Linux, and App Store app that (putting it simply) makes your iTunes (or Winmap or Rhythmbox) library available on the internet for you and your invited friends.

So, how it works! The first step is to download and install the desktop client. This has versions for Mac OS X (10.4.x and 10.5.x), Windows (XP and Vista) and Linux. When you launch the app for the first time it presents you with a user agreement, past that you get the required step of setting up your user account on their servers. This is done in-app and then set up for automatic login on launch (the app itself is set to launch automatically on login). After all that you’re presented with the main application window, it looks a lot like an IM client. At the top is a button to invite up to 30 friends. Once you have friends set up their iTunes libraries (annoyingly yours too) is displayed in the SHARED section of the iTunes sidebar. The cool part is that it works regardless of iTunes being open on their computer and regardless of you being in the same country, much less local network. But, for it to work the app has to be running (there’s a preference for either the Dock or Menubar to run the app in).

They also have an iPhone App (App Store link) that allows iPhones and iPod Touches to stream the content when available. This means that as long as your computer is active on an internet connection, you’ll have access to all your music (as not all of it may fit locally on the device) as well as your friend’s and/or family’s music libraries. Currently the iPhone app is free (as is the desktop app and service), but after 100,000 downloads it’ll cost $4.00.

Some may ask about Apple killing this service, my assumption is that as they’re not breaking any of the SDK rules for the iPhone OS, and they’re not streaming purchased/ DRM-encoded music that Apple will let them be (but only time will tell). Enjoy, Alex.