What's you experience implementing healthier habbits/manage health conditions using health apps?

I am an intern at TherAppX, where we reduce the noise in the numerous health apps to help digital health tools integration in the continuum of health care. I am curious about what components of an app will make a difference in the eye of the user. We launched a product today that helps choosing health apps according to the user's needs and I was wondering what were the major components that makes you adhere to one app instead of an other? Do you have any favorite features? What are the red flags about sharing your personnal information that will prevent you from using the app? Do you look for validated content? Is it the price? Let me know! :)