This is a simple and easy-to-use smart APP that can be used to find the device in both directions. After the device is successfully connected to the APP, click the alarm button in the APP on the phone, then the device will buzz; On the contrary, when you want to find the phone, just double-click the key on the device, then the phone will make a sound; When the Bluetooth connection between the device and the phone is disconnected, the device and the phone will alarm, so as to achieve the bi-direction anti-lost function.