Thank you very much for using our product, the App is a companion app for our watch. The App can synchronize data such as steps, calories, mileage, sleep and exercise records recorded by your watch. Your data is displayed in a more user-friendly and beautiful way. After you bind and authorize, we will push the phone call and text message content to the watch to prevent you from missing key information. You can use the App to configure the watch's sedentary reminder interval, alarm clock, schedule, backlight, and weather synchronization, so that you can use the watch better. Supported watches: For R4/SMA-R4 series watches, if there is follow-up update support, we will update them in time. If you have any questions, you can contact us at any time. Thanks again for your use.