I don't really know much about them, my husband went on a health kick started last year, lost 3 stone, have up smoking, gym, runs (Forrest Gump dosent have a look in) he uses Nike fuel band and an App on his phone which tracks everything weight lose, nutrition, heart rate, sleep. I think there is loads of different ones. One of the ladies on here mentioned one she was using not that long ago, hopefully she will read this x