The app seems to do most things well, except the main purpose for which I bought the watch - to track daily calories burned. After an intense, hour long workout that my old bodybugg and numerous online databases indicate should have burned 500-600 calories, the app shows I burned no more than about 200 calories. Its possible my expectations are incorrect, but I dont think so. The app seems significantly out of step with most other sources of calorie burn data. Consequently, I dont trust the calorie burn data, so I am not as diligent about tracking calories consumed in My Fitness Pal, as I dont have confidence in the net deficit calculation.
I love the step, weight, sleep, and heart rate tracking capabilities, but my main concern is tracking daily calories burned, and that seems to be no more than an afterthought in the design of this app.