The document outlines 6 rules for effective user onboarding for digital health apps. The rules are: 1) Ask for minimum user data and explain why it's needed; 2) Clarify what data is shared when signing up via social media; 3) Allow users to go back in the onboarding process and see progress; 4) Tailor the experience to the user's goals; 5) Don't require payment details for free trials; 6) Design the home screen around the main app functions and tasks. The purpose of onboarding is to prove the app's value quickly with few obstacles.