I updated my Fitbit Android app yesterday - the new app is labeled "beta" and was able to sync with my new Samsung Galaxy S4 phone. sync went smoothly - if you initiate the sync when the phone's bluetooth is off, you're asked if you want to turn bluetooth on. You might want to turn bluetooth off after the sync if you are not using it for other purposes - although I haven't had any battery life issues with the S4 so far.