Abstract: The present disclosure provides a user interface, a method, a system and an electronic device for providing channel indexed contents as an over-the-top (OTT) service. The user interface, the method and the system may be implemented on electronic devices to provide a “channel mode” other than the default operation modes of the electronic devices. In channel mode, content are selected by inputting a channel index value using a remote controller or a smart phone, and the electronic device then retrieves the content according to the content address corresponding to the channel index value. More specifically, the electronic device switches from its default operation mode to the channel mode when the electronic device is connected to an external display, such as a television. Therefore, the electronic device may provide a large-screen experience for OTT services with a large-screen device as an external display.