The app is free, but it only works for people who subscribe to both video and Internet service from Time Warner Cable.

Even then, it only works in the home, when the iPad is connected to the company’s cable modem via a Wi-Fi router.

Rob Marcus, the company’s chief operating officer, says the app will play 30 basic cable channels to start, but that number should expand soon.

Other major cable companies have iPad apps that play video on demand or act like big remotes. Comcast, the largest, has promised that its app will play live TV before the end of the year.