Frequently used apps.
I often use a fitness app called STRAVA.

It is an app that allows you to keep track and analyze your activities and mostly used for running and cycling. It is very convenient how it can record your performance stats like distance, time, route, pace, etc., just by letting the app run while doing your activities. It can sync with other devices like your phone or GPS watch to monitor your heart rate.
The app also allows you to connect with your friends like Facebook and you could both follow each other’s progress or do activity together. You and your friends’ activities are automatically uploaded on the app. It is an innovative application that improves a person’s motivation to be fit while having fun doing it with friends.
I highly recommend that you give it a try.