VKTECH Smart Bluetooth Bracelet Watch Pedometer Calorie Counter Sport Activity Tracker Accurate data sync between your bracelet and the app, it can even detect how many times you woke up during your sleep period Waterproof function: no problem in 30m depth. You can wear it to have a bath or even swim. Call reminder: For Android OS, display the in-call number; For iOS, display INCOMING CALL Smart Alert: Coming call alert, idle alert, sleep time alarm App download: E02 App named Body Sensor, you can download it from App store or Google Play; And the Android must be Android 4.3 OS, iOS 7 or above which is compatible with Bluetooth 4.0