For iOS, there is some basic Health integration, if the corresponding setting is turned on.
But I feel like, there’s so much more potential, because currently, it only adds data to the Activity Energy and Workouts section, one of the three Fitness Rings.
Freeletics tracks the amount of minutes one has trained anyway, so why not add that data to Health as well? This would mean you get the second ring as well.
Exercise Minutes tracks the amount of minutes exercised as well, so Freeletics should be able to add data there as well.