There are a vast number of Fitness Apps available for both Apple and Android, ranging from nutrition databases to sleep monitoring, wellbeing and exercise tracking.
For runners, Runkeeper is one of the most popular apps and will sync with a Polar HR monitor and also a smartwatch. Alternatively, Runtastic works with Spotify to allow you to control your running soundtrack. Stava and Endomondo are popular for both runners and cyclists. For Yoga enthusiasts there is a wide range of apps to help you work out at home and learn new positions. My Fitness Pal and Lose It are popular food tracking apps, while there are a large number of sleep tracking apps to monitor you through the night!
Try out a few free apps and see if you find them useful, but don’t overload yourself. A real benefit of exercise is the time spent offline, letting your brain and body focus on real life.