I had the same problems as others with the band not syncing sleep data following the app update. I could actually find the data on my phone by clicking on the graph icon in the sleep function but it was obviously not working properly as it told me that it could not sync. I uninstalled the app and tried to reinstall it. I cannot get past the welcome screen and cannot get the app back running. It keeps asking me to set up an account. Very frustrating. Also, I find the heart rate monitor unhelpful. You have to stop your workout, pull out your phone etc. I want it to work while Im working out and tell me my peak heart rate. Thats a minor criticism compared to the app problems. Right now Im wondering if my band is another piece of technological garbage that I seem to accumulate.
Robotlaw about Zepp Life (Formerly MiFit), v2.0.4