Tab for Google Reader is a system utility that lets you access your Google Reader feeds from the menubar. It is a very simple application that doesn't have any complicated features or basically anything that can get in the way of reading your news. After you log in with your Google account, the application will start showing you your unread articles. These items are shown in a small window that you can scroll up or down. The title of each article is shown in a bold font, and next to it you will find the name of the feed it belongs to and a small description. Some articles can be seen in their full version when you click on the title, but most of them will show a summarized version. For the latter, you will need to click on the title again to open the full article with your default web browser.
I like that the application lets you manage your feeds straight from the menu bar, without having to open a separate tab to do that. You can add feeds by name or search for new ones. You can also choose which feeds you want to see articles for. By default, Tab for Google Reader shows all your feeds.
There is a couple of things that this app is missing, like automatically telling Google Reader which articles you have already browsed so that your account can be synced with that information. You can do this manually after each page of articles, though.
In short, Tab for Google Reader is a nice app for any Google Reader user that wants to have quick access to his news. Unfortunately, Google Reader will be discontinued in a couple of months so this application will cease to work then.