"RTHK Audio Description" is a TV programme mobile app developed by Radio Television Hong Kong (RTHK). Simply with a mobile device you can enjoy the Audio Description (AD) service through listening to the AD sound tracks when the selected live programmes are broadcast on RTHK TV 31. In this way the visually impaired people cannot only enjoy RTHK’s TV programmes with AD on their own but they can also share the experience with their family members sitting together who listen to the original sound track from TV sets simultaneously.