Firstly, to use the Mac App Store, you’ll need to upgrade to OS X some.6.6 via Software Update. Once installed, you’ll have accessibility App Store via a blue App Store icon in your Dock or via your Menu Bar. The new icon looks a lot like the new iTunes icon. Start the app and you will be greeted to a view which would remind you of the iTunes store. On the top you possess a simple bar with forward backward controls on the left, icons to the five main categories of the store in the middle and a s