Fitbit is widely known and used across the world as a capable tool for exercise and diet goals. Reviews from the App Store rate it 4.2 out of 5 stars. The basic version is free to download and use, while the premium version is offered for $79.99, annually. The App Store posted confusing prices for the monthly premium subscription. It lists it as both $9.99 and $7.99.
Fitbit has many resources — possibly more than some may choose to use. For exercises, it allows you to record workouts, runs, and heart rate. For diet, you can set goals and log foods to see how they compare. You can also track your health data, such as weight.