Due to their technical characteristics, complete synchronization between iPhone and iPad apps is impossible. Only Challenges will reflect and update your progress on both iPhone and iPad. That's why we recommend using the app only on one of these devices.
With a much bigger screen, the iPad is convenient for our workouts. So it is up to you whether to choose iPhone or iPad for the app usage. You can use both, but please remember that your progress will not sync.
We do appreciate your kind understanding.