This app is AWESOME! I've been using it sporadically for over 10 years and it is nice that I can see my weight over that time period. Also, I don't use it fully but I do log my food. I have created some recipes and it is VERY USEFUL as a Food Log. It also used to sync with my SmarTrak app for my scale but that seems to have broken. That was on my Samsung Galaxy SIII and S5 Active though and I'm on an iPhone 8plus now. It also used to sync (on my Galaxy) with my Fitbit Charge HR but I don't know why it isn't sync'd now. Anyway I love MyFitnessPal and if I can figure out the Friends thing I will buy it so I can Timestamp my food and export data to Excel.
I'm using a Fitbit Charge HR again and it has SEVERAL ISSUES. Notably, on 12.3.17 I was able to confirm that it reset my calories for the day, presumably at midnight, from where they ended at 1206 when I plugged it into my computer and displayed 247 calories burned when I put it on at 3:10am before a workout. Those 247 were phantom calories. The Stairs/Floors didn't increase but I know they are not accurate either. and I think it also had me at .01 miles and I don't know if that is how far it is from my computer to my workout room about 40 feet away or not. I hope the Fitbit counts the calories right when I workout. I log the start calories and end calories and do the math. It seems reasonable but I am going to replace the Fitbit with an AppleWatch I expect. Alas.