I admit the app does track exercise quite well, but doesnt appear to use effort (HR) in calculation of calories burned, it only appears to use distance so is very inaccurate for treadmills, stationary bikes and rowing machines. The Apple Watch app is terrible and half the time fails to register and wont let you initiate an exercise from just the watch - first have to log in on your phone. The login function is also annoying - because I dont want to link to a Facebook account the app insists that I type in my full account name and password every time I open it. I paid for the pro but can definitely not recommend you spend the money.