Lang player is a free mobile application developed by EBS Korean Educational Broadcasting System designed to provide paid mobile video services. It allows users to purchase courses and lectures on a PC or mobile device. Once installed, users can log in to the EBSlang mobile site and access the virtual classroom to choose the desired lecture. The app supports streaming or downloading of course material, and users can adjust playback speed, repeat sections, and lock screen rotation. Lang player has a user-friendly interface with screen swiping and vertical/horizontal playback mode options. Note that streaming may be interrupted in unstable internet environments. Also, downloading requires sufficient storage space on the device and initial online playback. For any inquiries, users can contact EBSlang customer service.