Mi band app is not so good. The app not save the old data to campair the new latest data so it’s beg mistake. Sleep not monitaring when you sleep after 8 am so it’s another failure becouse more peoples are job at night and so they sleep at morining 9 or 10 am so this peoples are miss this feture. So in upcoming bands xiaomi this feture is upgrate and all time sleep monitaring device create.also it’not moniter of users heart rate. And the charger not produce only charger cable so it’s another mistake by xiaomi. I hope xiaomi in upcoming band all requirments are fullfilled.