Boxcar is a push notification app which works with the iPhones and iPads, in this one app you will be kept informed on whats happening with your email account(s), Twitter, Facebook, RSS feeds, and more.
While Boxcar isn’t a new release, it used to be a paid app, which has been converted to a free, ad-supported version. After you install it, head to Settings -> Add and Edit Services to set up push notifications for the various services you’d like push notifications for. While the Twitter and Facebook setup is pretty straightforward, you might need to practice before getting the e-mail function to work properly.
Most would agree that Push notifications are one of the best features of the iPhone OS, and Boxcar easily adds push to the services you’re most likely interested in receiving push notifications for. Even better: It’s now a free download for iPhones, iPads, as well as iPod touches.
For more information see the Boxcar website: Link