I was sick of how limited VeryFitPro application was so i wrote a program to copy data collected from the smartwatch. I compared bluethoot log from my rooted phone with logs of the application to understand package structure and data meaning. I didn't dig into every other aspect other than data logging (heart rate, sleep and activity) because I only needed those, then changed watch. If someone needs to dig deeper this is a good starting point.
* python >= 3.7
* bluepy
* Wireshark to analyze btsnoop_hci.log