First go to Google Play to download and install the Fitbit App. Then refer to this example to quickly set up the App. Don't forget to turn on Bluetooth to allow the App to detect the Fitbit Charge HR and sync with the HTC 10.
Fitbit goes the extra length by giving its users handy tips on how to use the Charge HR effectively.
When your phone has been set up successfully with the Charge HR, the App will be able to sync automatically with the tracker where your fitness stats will be displayed on its Dashboard page. You can also make your workout more interesting by creating your own challenges and connecting with other users and friends to share your status or experience.