I am surprised at how cumbersome and useless the app is and the data presentation. I thought fitbit would be the best being more mature but I am not impressed. Sleep tracking is way off. Apparently it starts recording an hour after you go to bed? Sleep apps show I fall asleep in 5 min with audio. I bought the charge 5 for the Spo2 measurement but it's not constant or real time, it only shows you a useless graph image of your sleep. I need more accurate and real time plotting if all measurements