The P9 is not listed as a compatible device. That doesn't mean that it won't work. My trackers work fine with my LG G6 and that is not listed either. If you want to buy a Fitbit tracker, I would buy it locally so that you can return it if it won't work with the phone. Also if you do buy him one, have him set up his account on a PC or a device you know is compatible and add the tracker and customize the settings (notifications, clock faces, etc.). Then when he downloads the Android app to his phone and logs into the account, it will already be set up.
