Using Health, Activity, And Fitness Apps To Monitor Your Health

I was not sure whether this thread fit better under the technology section or here; but since it is mainly about apps and devices that help us monitor our health and fitness levels, this seemed like the more accurate place for this thread.
We have had some kind of activity monitors for quite a few years now, and with the advent of cell phones and tablets, the advancements in fitness tracking have really skyrocketed, too.

First came the little pedometer that clipped on, and maybe next, it was incorporated into a watch. I remember having one of those watches that would keep track of my steps when I walked.
Next, I had a Fitbug, which was a little gadget that clipped on to my clothes and tracked my steps and then synced it into my iPad and iPhone.
I had to change the battery every few months, so I looked for one that charged up with a usb connection, and got one of the older Jawbone UP trackers. This one also tracked my sleep; so I could see how well I was sleeping each night.

I used that until last fall , when my daughter upgraded to the new Apple Watch cellular, and gave me her old Series 2 watch.
I didn’t think that I would like it , nor having to wear a watch again after all these years of not wearing one; but I now just love all of the things that this watch does.
It is not only a watch and a wrist-phone; but also as a device to help me monitor my health.

The Apple Watch tracks my steps, how many calories I actively burn each day, what my heart rate is at any time, as well as keeping track of how well I am sleeping.
When I go swimming, I can set the activity tracker for swimming, and it tells me how far I swam, how many laps I swam, and how my heart rate was when exercising. It also works the same way for walking, bicycling, and many other fitness activities.

The Apple Watch syncs with my iPhone, which sends the information to another app called “Health” .The health apps logs in all of the activity information, plus my food intake.
I have an app called “CarbManager” and when I eat, I record it in the app, and it keeps track of how many calories, carbs, fats, and fiber I get every day.
The health app takes the food information and shows me how many vitamins and minerals I am getting from the food that I eat, so I can easily track my vitamins and minerals, and see what I might need to supplement with, and which ones I have enough of in my diet.

There are a lot of health and fitness apps available for people who care enough about their health that they want to keep track of everything, so regardless of what kind of phone or computer you use, there are programs that will work for it, and apps that integrate easily with most phones.
What I would like next is one of those scales that works with a phone app and shows not only your weight, but your BMI and other related info.

I know that one popular food and diet app is called “My Fitness Pal”, and I have seen all kinds of sports and walking/running apps ; but the ones that I have do what I need to have done.
Which other apps are any of the rest of the folks here using, and why do you like them the best ?