Fitbit has everything I need, the steps, the Heart Rate, it has all of my exercising modes, and it has a fair price. It has a rather simplistic User interface, which I really like to be honest. Highly recommened!
CardioX - CardioX AI powered mobile app can estimate blood pressure, heart rate and calculate all major HRV parameters.There is no need for any medical devices, only CardioX mobile app and a smartwatch with ECG capabilities(or portable ECG monitor).
Strava - The #1 app for runners and cyclists
Magic - Get whatever you want on demand with no hassle, through SMS
Lose it! - Snap a photo of your food to get nutritional facts
Smoke Free - Virtual "Quit Smoking Buddy" in your pocket
Workouts by Muscle Booster - Workouts by Muscle Booster is an app that provides you the home as well as gym workout plans.