how can I get the fitness app?

What Apple Watch do you have?

Yes, you need one. Apple Watch personalizes your Apple Fitness+ experience by integrating your personal metrics, like your heart rate and the calories you burn, into every workout. It brings them to life on the screen to keep you informed and motivated. To use Apple Fitness+ on your iPhone, iPad, or Apple TV, an Apple Watch Series 3 or later is required.

Apple Fitness+ is available in

1. The United States
2. Canada
3. Australia
4. New Zealand
5. The United Kingdom
6. Ireland