In the new iOS 9, Apple will no longer provide a way to trust Enterprise Developer Profiles when they are first downloaded. The Body Code 2.0 is not sold in the App Store and so it requires an Enterprise Developer Profile. Due to this update users will have to manually change the settings after downloading the application.

To do so, open your Settings then go to General -> Profiles -> select Wellness Unmasked and press "Trust this application" ( or try General -> Device Management -> select Wellness Unmasked and press "Trust this application")