If your Android device’s screen is off, your One will not sync in the background until you wake your Android device from sleep. Force Sync You can also Force Sync your tracker through the Devices menu to get the latest data synced. To Force Sync your One tracker: 1. Open the Fitbit App.f you already have the Fitbit App installed, make sure that you have the latest version. 2. Plug your charging cable into a USB port and insert your tracker into the charging cable. 3. Enable Bluetooth on your mobile device and within the Fitbit app. 4. Make sure your mobile device is connected to the Internet.