Comcast (CMCSA) today unveiled the Xfinity TV app for the Apple (AAPL) iPad, which will allow the company’s cable customers to watch TV shows and movies on the tablet. The free app also can be used to browse or search TV listings, as well as to change channels on your TV and to program your DVR. The app launches this week; the ability to watch a select set of video content on the iPad starts in December. The company said it plans to offer additional apps on the Apple iPhone and iPod Touch, Android OS, and BlackBerry devices and other platforms.